# Ford 850 Engine Problem



## ErnieChilton (Jul 25, 2014)

I have been posting to the Ford Forum but think I have exhausted my sources there. In desperation I thought I would try the Repair and Technical forum this time. I have a 1955 Ford 850 Tractor with a 172ci overhead valve engine with a Marvel TSX593 carb. The tractor was given to me and had a badly rusted frozen engine. I completely rebuilt the engine; new valves, pistons, sleeves, crank, points, cap/rotor, plug wires and a complete carb rebuild kit. After this, it initially ran good, but would not idle below 1200 RPM and adjusting the idle fuel needle had not effect. I had problems rebuilding the cast iron carb. Could not get the float seat or idle jet out. Cleaned it all out the best I could, but remember, it ran good around 1200 and above.

After a few months checking out the hydraulics, transmission, clutch, etc, I decided to go back to the carb and took it apart again and cleaned every passage way I could and reinstalled. Same problem, so purchased a new Zenith 13877 carb. Installed it and the engine would barely start and “blubbered”, black smoke out the exhaust and would not run more than a few seconds. Checked the float level in the Zenith and it was OK. Idle adjust had no effect. By this time I decided to return the Zenith and remounted the TSX593 MS carb. IT DID THE SAME THING, “blubbered” and seemed to run very rich. Nothing had changed from running good at 1200 rpm except for trying the Zenith.

I then rechecked the TSX carb and managed to get the float valve seat out and the new one installed. Stopped “blubbering” but the engine would not run. Would fire a few times but never catch and run.

I have been working this problem for 6 months and desperation has set in. Finally I turned my attention from the carb to the ignition. Checked compression and all cylinders around 125 psi. Getting a spark at all plugs. Checked point gap and statically retimed the ignition at 4 deg BTDC using a 12V test probe. Then I noticed that at TDC the rotor was not pointing directly at the cap #1 electrode but was lagging it be about 15 to 20 degrees. Tried moving the distributor gear forward one tooth, but it still did not point to the #1 electrode. Moved the gear forward one tooth but still would not align with the #1 electrode. Engine would not start with at either setting (but I did get a few nice backfires). Reset the distributor to the original position and managed to get the engine to start and run roughly for about 15 sec by advancing the distributor base about 20 deg.

On thing I noticed but don’t know if it is relevant is the new dist cap had a #1 marked on the inside but I could never get the rotor to point at that electrode at TDC. Don’t see how that could be a problem as long as the 1243 firing order is maintained.

Please, if anyone can offer any suggestions, I would really appreciate them before I go crazy.


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## cviola2005 (Feb 16, 2016)

Are you sure it is firing on the compression stroke TDC and not exhaust stroke TDC?


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## ErnieChilton (Jul 25, 2014)

*Re: Ford Engine Problem*

Thanks Cviola for the reply. I believe I should get significant blowback thru the carb if all cylinders were firing on the exhaust cycle, I can’t believe the engine would run for 10-15 sec under these conditions. However, since I am grabbing any straw I can find, I will pull the valve cover verify if the #1 valves are closed. I have detailed my timing process below to see if anyone can find a fault with it. Obviously I am not correcting the problem and need some independent thoughts.

I have redone the timing statically several times by monitoring the voltage at the coil terminal with a test light. When the light comes on, it indicates the points have just opened. I check for the beginning of the compression stroke on #1 and then look for the timing marks on the flywheel thru the tiny 2” inspection window. This is an exasperating job because the manual says to use a screwdriver to lever the flywheel to expose the marks in the window. Unfortunately the hydraulic manifold is positioned directly in front of the window and you can only use a small stubby screwdriver. Very slow process.

Setting the timing marks is made more difficult because I remove all spark plugs, which prevents the crank from bouncing back when the piston starts a compression stroke and you hit the 6V starter with 12V, (great for starting but the timing marks fly by pretty fast). Can ’t turn the crank directly since there is no bolt to use a wrench. I can however, turn the crank slightly by using a fan blade.

I believe I am being confused by too many assumptions based on several conflicting set of facts. 

1) Prior to the TSX to Zenith carb swap, the engine originally ran like a top, just would not idle below 1200 rpm. I even drove it around for a few minutes. This should indicate that the firing order, cam timing, etc is OK.

2) After the original swap neither carb would run more than a few sec and both seemed to run excessively rich, seemingly indicating that it was not a predominately carb problem since the rebuilt TSX and the new Zenith gave the same results.

3) Timing was not changed during the original carb swap process. Since then, I have reset the timing several times, with the same results.


4) The engine will not run with the timing set a 4 deg BTDC, but will run roughly for 10-15 sec if the timing is advanced by turning the distributor counterclockwise. But it doesn’t run long enough for me to get a strobe light reading.


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## cviola2005 (Feb 16, 2016)

ErnieChilton said:


> Thanks Cviola for the reply. I believe I should get significant blowback thru the carb if all cylinders were firing on the exhaust cycle, I can’t believe the engine would run for 10-15 sec under these conditions. However, since I am grabbing any straw I can find, I will pull the valve cover verify if the #1 valves are closed. I have detailed my timing process below to see if anyone can find a fault with it. Obviously I am not correcting the problem and need some independent thoughts.
> 
> 
> 
> ...



It sounds to me like you have another problem. Forget everything and go back to the basics, like the fuel filter. Verify that you are getting adequate fuel delivery into the carb bowl. Then verify spark plugs are not fouled and are correctly gapped. Verify firing order, then ignition timing. If all those things are lined up correctly and still wont start, check compression.


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## pogobill (Jan 31, 2012)

I'll do a little investigating, but could it be an issue with the governor or the governor rod? I had a heck of a time with my Cockshutt 60 and for the rod sticking causing the tractor to shut down after a short period and not restart.
Just a thought for now.
I guess the distibutor isn't 180 degrees out?!? Sounds like you have addressed that already. The initial timing spec at 475 rpm is 5 degrees BTDC.


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## TraderMark (Nov 15, 2011)

I'm no expert on old Fords, but are you sure about that firing order?

I don't think I've ever seen that firing order before.

Every 4 cyl engine I have ever worked on, gas or diesel had a 1342 firing order.


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## cviola2005 (Feb 16, 2016)

I used to think the same thing trademark, but then I found a few odd balls with a goofy firing order. I'm not sure about this engine either, but he said it was running and driving before. I guess he could have mistaken his firing order when he pulled the plugs.

Tractordata shows the firing order to be 1-2-4-3.


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## pogobill (Jan 31, 2012)

That is pretty much the same firing order that ford has used on it's tractors since the 9N. 
ErnieChilton... Did you also change the coil? Could mean you either need to run with an external resistor or need to run without one. 
Sorry I can't be of much help, I only have a couple of 8N's, and not an 800 series tractor.


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## TraderMark (Nov 15, 2011)

Wow.
I learn something new every time I come here!!!


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## ErnieChilton (Jul 25, 2014)

Cviola – Compression is 125 psi on all cylinders, low but this is a new engine and the rings have not yet seated. Fuel getting to carb is not a problem, if anything it is running rich. I have not mounted the tank yet but use a Folgers (chosen because color matches the vermilion red of the tractor) with an inline filter and shut-off valve. Fuel can be drained from bowl and float level checks OK. Plugs are gapped to .035 (also tried .025 gap but got same results) not fouled but black from rich or incomplete combustion. Firing is 1243 as per manual and timing is set at 4 deg BTDC per the Ford manual, Advancing the distributor about 10-15 deg by turning counterclockwise results in no improvement, but the engine will not run when it is retarded by the same amount. The timing is set by turning the distributor until the points initially open, but at this position the rotor lags the #1 terminal about the width of the rotor tip (looks like the leading edge barely makes contact with the terminal post). The manual says to reposition the distributor gear 1 turn if you must turn the distributor more than 10-12 deg so the rotor points at #1. If I try repositioning the gear to advance the rotor, it is moves about the same distance on the other side of the terminal and will not crank and run. Since the cap position is locked to the distributor and cannot be changed, I cannot position the rotor to point directly at the #1 terminal, but it is obviously making contact because it does fire when I crank the engine over and I can get a 3/16” spark to #1.

Pogobill – Prior to this, I had not messed with the governor rod, primarily because the last thing I wanted was another variable. So I disconnected the governor rod and replaced it with a manual set up, but that had no effect. However, when it ran good at 1200 rpm before I started this ordeal, I had to open the throttle lever about half way to get it to start and run. The centrifugal advance should advance the cam lobe by 12 deg at 1200 rpm. The distributor has an oiling spout attached to the base, physically preventing it from going in with the spout pointing toward the engine. By my reasoning, the distributor can be inserted in any orientation as long as the rotor is pointing to the #1 terminal when the points initially open.

After all this, I stop and remember that the engine ran good with exact same ignition setting, same components, but just would not idle below 1200. Unless I get an “Ah-Ha” moment, I will leave the ignition boon doggle and reopen the carb investigation, where I had 2 carbs, one brand new Zenith, one rebuilt TSX593, both exhibiting the same problem and appeared to run rich. Next step is to fill the carb bowl and then shut the fuel to the carb off. Then start the engine and try to get it to run long enough to where the engine will lean out when the fuel level in the bowl drops and see if it runs smoothly for a few seconds. 

Guys – I must apologize for my lengthy posts, but I want to detail exactly what I am doing as precise as possible in hope that someone can spot a dumb ass mistake, which I have been known to make. My primary engine experience, except for rebuilding my ’67 Ford F100 engine several times, has been with fuel injected, methanol burning SBC’s with magneto ignitions. When I started this project I thought “what a simple engine, this is going to be a piece of cake.”


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## cviola2005 (Feb 16, 2016)

The rotor will be close to the post when it fires, and not centered with with it. I hope that makes sense. The carbon left from the spark will be indicative of those on any distributor. It's always carboned on the leading corner of the rotor and the posts. I don't think you have an ignition problem.

I believe your problem is completely carb, and this just dawned on me. The carb has an idle circuit, which is only used for idle, up so many rpms. The main jet is used above said rpm, which is why it ran before above 1200 rpm, but not below.

Can you post some pics of this carb?

Have you tried lately to start it with the throttle open about halfway?


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## ErnieChilton (Jul 25, 2014)

Civiola – 

I agree, I think this has to be a carb problem. I retimed the ignition for the umpteenth time this weekend and have redirected my effort to the carb again.

A quick review of what got me to this point.

1. Put a complete TSX593 rebuild kit in. Remember this is a cast iron carb and had lots of rust, Could not get float seat or idle jet out soaked it for 1 month in rust remover and cleaned as best I could. Engine ran good, would not idle below 1200.
After a couple of months trying to get it to idle, decided I would admit defeat and buy a new carb.

2. Purchased a new Zenith 13877, a replacement for a TSX706 that superceded the TSX593. New carb replaced perfectly except it has a fixed power jet instead of the adjustable one on the TSX. One less adjustment to make.

3. Could not get new carb to run more than 10-15 sec. Appeared to be running rich, heavy black smoke and “blubbered”. Idle adjust had no effect. Checked float level and it was OK. Put back on, same problem. Disgusted, I returned Zenith carb.

4. Put TSX593 back on and IT DID THE SAME THING as the Zenith, running rich. Could not get it to run more that a few sec and black smoke, etc.

5. Now I assumed I had developed a new problem. Since the symptoms were the same with both carbs, one brand new, I assumed a new problem had developed and the ignition seemed the logical culprit. Hence my ignition boon doggle.

Now I am going to ignore everything but the carb running rich, if I can solve that and get it to run as well as it did initially, then I will be happy. If it runs but won’t idle, then I will work that problem separately.

Yesterday I disassembled the TSX593 and, after 7 hours, got the float seat and idle jet out and replaced them with the new parts from the kit. Ran small wires through all passages and blew them out with carb clean. Mounted the TSX on the engine except bypassed the governor and connected the throttle directly to the linkage.

Attached is a jpg file of the TSX593 IPB, a jpg of the carb mounted on the engine, and 2 pdf pages from the manual describing the fuel circuit operation. Hope we won’t need them. I am now ready to try starting again. I have been disappointed so many times in the past at this point that I have to build up my courage to try to starting it. Wish me luck!


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## cviola2005 (Feb 16, 2016)

Don't feel bad, Ernie. I once had a CubCadet lawn tractor with the flat head ford 4 cylinder. I tried everything I could think of (I was about 14-15 years old) to get this thing to run. One time, I drained the tank, fuel line, and carb bowl. I forgot to put the drain plug back in when I filled tank with fresh gas and the darned thing started up and run great like that. But when I tried to put the plug back in, it would die! And it would not run unless that plug was removed! I never figured out why it worked that way though. 


Anyways.... I have a few thoughts in mind. First thought is that maybe the float arm is bent in such a way that the needle doesn't seat and floods the engine.

Second thought is the verify that the choke is working as it should. Maybe the relief valve is stuck closed? Or maybe the choke isn't opening completely?

Third thought is to try closing the main adjustment needle all the way and try starting it with only the idle circuit. If it runs on the idle circuit just fine, then something must be wrong with the main circuit or the setting you had it at was too rich.

Hope this helps


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## ErnieChilton (Jul 25, 2014)

*Ole Ernie vs the TSX93 Carb, Round 3*

Cviola -

Have not been able to spend much time on the “tractor project from hell” lately, weather turned nice and lots of things to do around the farm (I use the term farm rather loosely, if poison oak and honey suckle were cash crops I would be rich).

I have dissembled the TSX for the umpteenth time again and poked wires through all the passages, blown carb cleaner through all the passages, and checked the float level. When I turn the carb upside down and blow into the fuel inlet the float valve seals off the fuel passage. When I turn the carb right side up and blow into the fuel inlet, the needle allows air to pass, so it is open. The TSX is an updraft carb and the fuel system is gravity feed. With the carb mounted and fuel lines reconnected, it will sit for a week without leaking fuel, so the float valve is not sticking or otherwise allowing fuel to pass. If it did leak, I can easily tell by inserting my finger through the air intake into the bowl area to see if any fuel has puddled in the bowl. The choke is spring loaded to the open position and again, I can easily check its position by simply looking into the intake. The choke relief is lightly spring loaded and seems to open quite easily. However, since I have to hold the choke closed I cannot see if the relief valve actually opens.

This is what I discovered after trying to get it to run with the power adjust needle all the way in and the idle circuit needle ½ turn out (turning it in richens the mixture and turning it out allows more air into the circuit leaning the mixture) and choke engaged. Same results. Try to start, runs roughly with black smoke for a few sec and stops. After doing this several times, the engine appears flooded since I have to wait about 45 min before it will even catch again. I have been engaging the choke initially when first trying to start. After waiting a few hours between tries, engine will not fire unless the choke is engaged.

Now for something new. If I slightly crack the throttle and allow the bowl to fill, then shut off the fuel and spray a little ether into the carb intake, the engine will catch and run fairly good for about 5-8 sec till the fuel in the bowl is exhausted. I can repeat this procedure several times with the same results. However, If I try to start it with the choke and no ether, I can’t get it to run smoothly when it catches.

I have a fuel delivery problem of some sorts, but cannot pinpoint it. My next step will be to remove the sediment bowl from the carb and run a fuel line directly to it. If that does not shed some light on the problem I will purchase another new Zenith 13877 carb (which is a direct replacement for the TSX593) just like the one I previously returned at the beginning of this saga. If it then does not solve the problem, I will ask my doctor to prescribe an anti-depressant for me.


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## cviola2005 (Feb 16, 2016)

Try turning the idle curcuit screw out about another turn and try again?

How does the power adjust screw work? Turn in does what? Turn out does what?

Have you tried starting it with ether and open choke?


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## ErnieChilton (Jul 25, 2014)

1. Engine will fire but not run when I turn the idle screw out another turn which is leaning the idle circuit.

2. The power screw leans the engine out when you turn the screw in, just opposite from the idle screw. Turning it in or out seems to have minimal effect since I cannot get engine to run for any length of time if throttle is more than just slightly open.

3. When starting with either, I never use choke. The reason I tried ether was to prevent the flooding of carb when choke is used.


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## cviola2005 (Feb 16, 2016)

Isn't the power adjust screw to "give back" power lost due to age? Which would mean that it's not for tuning the main circuit, which is why it has minimal effect.

Does it attempt to run when starting with the throttle about halfway open? If not, I would try to lean the idle mixture all the way, then turn it in until it runs. Hopefully it will get to that perfect spot to make it run.


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## dpease (Jul 6, 2013)

I can really appreciate what you are going thru. I’ve just experienced so many or the same things you’ve been through. 
First would not start. Then I’d get it started - finally and it would run acceptable but would not idle.
Timing set and re set. New zenith to replace the Marvel. Tossed the points and installed an electronic ignition to reduce variables.
I was even to the point pulling the engine apart to confirm timing tooth alignment. 
(C-200 international engine which is a real pain as it serves as tractor frame as well)
My problem turned out to be a leaking intake manifold. 
Your picture shows how great your work turned out – I know you would swear an intake leak is impossible – I would have said the same but was desperate and decided to exhaust all possibilities before I tore the engine down again. I used a new intake gasket in the rebuild and it still leaked!!!
Not only have I had to reseal the intake once. Two weeks ago I had to reseal it again. 
It ran perfect at the end of last season. This spring back to another leak. This time I used hi-temp silicon. 
Sorry for the l o n g story but if I said intake leak and never told you how similar our troubles were –well... I hope yours turns out the same because it is such a simple fix


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## FredM (Nov 18, 2015)

G'day ErnieChilton

I have read and reread the posts about your problem, I wonder how many times a carby would need to dismantled and cleaned and reassembled with no improvement with the problem, I would assume the idle mixture screw and the power mixture screw would be set as per manual, the float level is correct,--- on your schematic I don't see a main jet, does the carby use a main jet at all or just the venture tube ?.

You mentioned replacing a few parts on the rebuild, I didn't notice spark plugs. or a new coil for that matter, I know you wrote that you had a 3/16" spark, --- would this be a good solid blue spark or a slight orange spark ?.

Does the distributor have vacuum and mechanical advance fitted ?, have you checked this by moving the rotor cap to the advanced position and check the rotor tip in relation to #1 firing position ?.



I feel the problem is either electrical or mechanical, I am known to be wrong, my wife tells me so.


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## ErnieChilton (Jul 25, 2014)

Thanks guys (I assume you are all “guys” but please don’t call the “politically correct police” on me if I assumed wrongly)

Quick Review

1. Engine ran good at 1200 rpm but would not idle. I assumed it was carb since the TSX593 is cast iron and was very rusty on inside. Hence the many attempts at rebuilding since I suspected internal passages contained rust.

2. Replaced carb with a brand new Zenith 13877 which is a replacement. At this point engine would not run at all. Would start but blubbered with black smoke. The Zenith only has a idle adjust screw and a fixed main jet. Could not get it to improve at any idle adjust setting. Disgusted I returned the Zenith for a refund.

3. Went back to the TSX593. IT THEN EXHIBITED THE SAME PROBLEM AS THE ZENITH!!! Would not run at 1200 rpm. Problem has gotten worse. After a few more rounds with the TSX, went to the ignition.

4. Distributor was rebuilt with new points/capacitor/rotor/cap and plug wires. New 12V coil with internal resistor. The distributor has a centrifugal advance only which seems to operate freely. Checked spark by attaching each plug wire to a 3/16” external gap (2 nails correctly spaced). Got a good blue spark on all 4 wires. Decided against electronic point replacement since it would use same cam, etc.

5. Pulled the valve cover (172ci Overhead Valve engine) to verify #1 TDC and that all valves opened/closed appropriately. Discounted a timing gear misalignment since engine previously ran good at 1200 rpm and is gear driven so it seems impossible to have slipped a tooth. Checked valve lash. Could not check valve open/close since I do not have any cam specs.

6. Back to TSX593. It does not have a main jet but the power screw regulates the fuel entering the venturi tube. Manual says “the power fuel system supplies fuel to the engine in the speed ranges between idle and slow speed”. 

7. I have purchased another Zenith carb, really ticked off because price increased $50 while I dinked around for 9 months!!!

Plan of Action

I had discounted a leaking intake manifold because the black exhaust pointed to a rich mixture and a leaking manifold should lean the engine out. However, since reading the post from Dpease will check it out. The intake/exhaust manifold on the engine is one piece, but it will be fairly simple to remove and check. I used all new gaskets in the engine rebuild but will reseal the intake with silicon, mount the new Zenith carb and, after making a suitable offering to the Tractor Gods, will try again.


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## FredM (Nov 18, 2015)

interested to hear the results of the 2nd new carby fitment, I hope this fixes your problem


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## cviola2005 (Feb 16, 2016)

Any updates?


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## ErnieChilton (Jul 25, 2014)

Carb Flooding?

After a short sabbatical from my nemesis the “Tractor From Hell”, I decided it was time to tackle the start/run problem. I had previously pulled the manifold and sealed it good as “Dpease” suggested, but it did not solve or change my problem. This time, I mounted the new Zenith 13877. It has a fixed main jet so the only adjustment is the idle mixture and the idle speed adjust screw on the throttle. After mounting, I turned the fuel shut-off on and let it sit for a day to make sure the float needle valve was shutting the fuel supply off. Then I emptied the sediment bowl, filled the gas container with fresh fuel and adjusted the Idle Mixture to 1-1/2 turns out. I did not use the choke for all starting attempts, instead put a quick squirt of ether into the carb air intake to make sure the choking action was not causing it to flood.

1. With this setting, I could get the engine to run, albeit roughly, for between 15-30 sec with the tach indicating about 1000 rpm. (Am beginning to wonder about the tach accuracy but will ignore this until I can get the engine to run acceptably at any speed) After starting, it begins to catch & run fairly good for a few sec then stumbles and starts to die, and then spits black smoke and catches again. It will go thru this cycle approximately every 5 sec. After a while it fails to catch after a stumble and dies.

2. Changing the Idle Mixture adjust has little effect, but will die if it is closed all the way. Sweet spot seems to be between 1-1/2 to 2 turns out. Opening the throttle will cause the engine to die.

3. After it goes thru one of these “run” cycles I can sometimes get it to start without ether.

4. After 3-5 cycles of running 15-30 sec, will not fire even with ether. Letting it sit for about 15-29 min can get it to start and run again. It appears to be flooding.

5. After one of these frustrating sessions, I took a break to do some other chores but forgot to shut the fuel vale off. When I came back, could smell gas and found that the carb had overflowed. I think the float valve is sticking on my brand new carb !!! It seems to be OK most of the time, but the engine vibration must be shaking it enough to leak.

Next step is to disassemble the carb and check float setting and valve. Don’t know if I have found the problem or just another rabbit to chase.


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## cviola2005 (Feb 16, 2016)

If it tries to die
Then black smokes and catches, wouldn't that mean that the carb is too lean and the governor is trying to keep it running?


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## ErnieChilton (Jul 25, 2014)

*Rich vs Lean*

I have disconnected the governor linkage from the carb so the throttle lever is the only control, spark plugs are solid black which indicates a rich condition. If it was leaning out, I would think I could richen the idle mixture, but idle mixture has little effect. The 1-1/2 to 2 turns out is the best setting, but not a pronounced difference. Also if it was leaning out, I would think I could catch it by pulling out on the choke, but doing this kills it immediately. My next step will be to eliminate any problem with the float valve and then start from fresh. Talking to locals that have experience with old Ford tractors say that they are famous for flooding problems.

Spring chores are slowing me down. Also working on the old Ford tractor ceased to be fun months ago.


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## FredM (Nov 18, 2015)

but you gotta beat it mate !!


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## BigT (Sep 15, 2014)

Ernie,

I wonder if the new carburetor has the wrong size jet (too large) in it?


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## mandoman (Apr 26, 2016)

*Its the spark plugs*

I will start by saying I have 40 years of experience working on these tractors. I do this for a living everyday. In the beginning you were doing alright with the Marvel Schebler carb, the only problem you had was a plugged idle air circuit. When you installed the Zenith carb it obviously had issues. It really doesn't matter what it was what does matter is that it fuel fouled your spark plugs. This can happen in a matter of minutes, believe me. I have seen it time and again. You crank over the engine it coughs a few times spits out black smoke sputters around then dies. You keep trying and voila the plugs are ruined. What happens is the porcelain down inside the plug gets cracked and now the plug will not fire at the electrode under compression. You need new spark plugs. Change them before you do anything else!!!!

Your cranking compression is good it only takes 90psi to make this engine hit. The leading edge of the rotor should line up with the #1 tower when the points are just beginning to open at top dead center of #1 on compression stroke. I usually just stick my finger in the number 1 plug hole and crank the engine and watch the plug fire. If I see the plug fire at the same time it blows my finger out of the hole it is close enough in time to run at least roughly. The dist. on these engines will turn far enough in both directions to get it to run smooth from there. 

I would put your original carb back on the engine. It is a much better carb than the zenith. I would then check to be sure you have either an internally resisted 12 volt coil or a 6 volt coil depending on what voltage system you are using. 
I would next set the point gap to .017 and check to be sure they are firing using an ohm meter to check the resistance of the points when they are closed, should be less than 2 ohms. Then I would turn the main mixture control needle out about 1 1/2 turns and the idle needle the same. I would open the plug on the bottom of the fuel bowl let the bowl drain and be certain fuel is running through the carb at a steady even flow. Then I would put the plug back in pull the choke out and crank the engine over a time or two. Push the choke back in and start the engine. Adjust the carb and timing as necessary. 

These carbs many times have to be re-jetted today to get these tractors to run with out a few spits and sputters at either idle or wide open or a hesitation in the throttle. Most of the time I just solder the jets in and drill them back out to the size I want depending on what the tractor is doing to make it run flawlessly. 
Good luck... 

Oh a couple things I forgot if you are wanting to check to see if the intake manifold is leaking put your hand of the inlet on the carb and crank the engine. If it sucks your hand up to it tight you have plenty of vacuum to pull fuel into the cylinders and make the engine run it may run rough and misfire but it will still start.

The other thing and this is important! Starting fluid and or ether can and will crack spark plugs and render them useless. Many times an engine will fire with starting fluid because it is much more volatile than gasoline especially todays gasoline. When you try to start the engine with gas after using starting fluid it will not fire on gasoline. Don't ask me how I learned this lesson, lets just say it wasn't on a 4 cylinder ford tractor where you can change the spark plugs in 10 minutes.


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## ErnieChilton (Jul 25, 2014)

*Spark Plugs ?*

Thanks for the replies, especially from "mandoman". I have not considered a spark plug problem, but will definitely replace them. It's worth $10 just to eliminate the possibility even if it doesn't fix the problem. Everything in the ignition system is new except for the distributor which has new points (set at .017"), capacitor , rotor, cap, and plug wires. The coil is a new 12V with internal resistor and I can pull a healthy 1/4" spark externally. All plugs have a good spark, but are externally tested and not under compression. It is difficult to gauge the exact position of the rotor to the #1 cap post because of the dust cover obscuring the rotor, but as best as I can tell the leading edge of the rotor is just beginning to touch the post when timed at 4 deg TDC. Putting a timing light on #1 shows it is firing at the 4 deg mark, but is difficult to observe accurately since the engine is not running smoothly. However, I realize that observing the existence of a current surge thru the plug wire just means there is a spark somewhere, not necessarily at the gap.

Will let you know how the new plugs work out, but it will be a little while before I try them, my primary work tractor (a Mahindra 575 DI) has a leasking water pump that I need to get fixed asap.


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## sixbales (May 18, 2011)

QUOTE: "Everything in the ignition system is new except for the distributor which has new points (*set at .017"*), capacitor , rotor, cap, and plug wires."

Is this a typo? The point setting for an 800 series tractor is .024" to .026", nominally .025". Set the points at *.025"*

Check/confirm this at John Smith's Old Ford Tractors website.

Spark Plug gap .025" - .028"


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## mandoman (Apr 26, 2016)

*Correct point setting*

Sorry I didn't respond sooner I have been out of town for a while, sixbales is correct the point setting of this engine should be .024 to .026. 

There is another thing you should look at. The terminal that goes through the distributor housing on these tractors has an insulator around it to keep it from shorting to ground. 

I would remove the wire and terminal from the distributor and inspect that insulator 
very well. Given you have such a strong spark at the coil wire and also at each of the plug wires, I really doubt this would prevent the tractor from starting. 

I have however seen this cause real problems after the engine is running. 

The insulator is small and thin and tends to crack. The crack will cause a short to ground in the wire coming from the points to the coil under some conditions and not others. Has cause me to loose sleep before. 

Once you get the tractor running a good dwell meter will give worlds of useful information about the condition of your distributor itself. 

Good luck let us know how things go.


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## ErnieChilton (Jul 25, 2014)

Thanks guys. My Mahindra work tractor is now running again so it is time to start on the “Ford tractor from hell”. I have been fighting this problem for over a year; 3 months trying to get it to idle below 1200; another 3 months troubleshooting the TSX and Zenith carbs; about 4 months going over the ignition system and going on four months back looking at the carburetion. Too bad I don’t get paid by the hour, however since I don’t get paid at all it don’t make much difference.

Yes the .017 was a typo, the point setting is actually .026” on my tractor. I will take a close look at the point wire insulator before I do anything else. Have 4 new Autolite 427 spark plugs which I will put in, put the old TSX back on, adjust the needle setting and pray.

Has anyone had any experience replacing the points with a solid state setup? I hesitate to add something new to the equation but am getting desperate here. If the spark plugs don’t solve it I am willing to try anything. At least with the old setup you can measure stuff, like points gap and timing the points opening.


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## mandoman (Apr 26, 2016)

*Too many variables = troubleshooting nightmare*

Ernie, the first thing I do in solving any problem is eliminate the variables. Introducing a new one by adding an electronic ignition system isn't something I would recommend. 
I have installed quite a few pertronix ignition systems on different applications per customers request. I have never been very impressed with the outcome. Usually I end up with an engine that has longer cranking times an doesn't run any better or worse than it did with the points ignition sys.

If the original distributor is in good condition ie the bushings are not worn out, the advance mechanism is in proper working condition, the cam lobes are in good condition and all are nearly the same height, the teeth on the drive gear are in good condition, the insulators are not broken, cracked, or missing. These units have performed well for many many years in millions of applications, for millions upon millions of hours. 

If your distributor is worn out already putting an electronic ignition system into a worn out distributor housing is likely only to create only more problems. 

Remember the tractor not starting and running all came from ONE thing changing. The installation of a different carburetor. The first zenith carburetor is what started the down hill spiral. 

I highly recommend getting everything back to the way they were before you installed the first zenith carb. except install the new spark plugs!


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## ErnieChilton (Jul 25, 2014)

Guys -

I finally got a chance to spend some time on my nemesis today.

1. Remounted the TSX593 carb, put new Autolite 437 plugs in, drained old fuel out of sediment bowl, put fresh gas in the “tank” and checked to make sure fuel was getting into the carb bowl. Set the idle screw at 2T out and power screw at 2T out (also tried with both at 1-1/2T out). Reconnected all linkages including governor. 

2. Set the idle speed screw so the throttle plate was cracked open, pulled out the choke and hit the start switch. 

3. After a couple of seconds, engine catches, I release the choke and it starts running fairly good at about 1000 rpm for a few seconds and then begins its old routine of dying, then spitting black smoke and catching again. It keeps repeating this cycle and will run like this for a couple of minutes before it finally dies. Restarting, it will run like this for another few minutes. However it does run long enough to for me to do some troubleshooting.

4. The idle screw has minimal effect, I can turn it all the way in or all the way out without any substantial improvement. Power screw also has minimal effect I can turn it all the way in or out with no improvement.

5. Opening the throttle causes the engine to die.

6. Connected my timing light to #1 plug wire and observed the timing marks on the flywheel. When the engine is running OK the timing is right on (5 Deg BTC) when it starts to die, the timing light does not fire until the engine catches again and goes through another run/die cycle. The timing light is my old Craftsman (about 20 years old) but has always worked well for me so I do not understand why it does not continue to fire the strobe even if the engine dies, since it is still turning the distributor.

All of my spark checks have been with the engine at cranking speed when I observe a good spark. Under running conditions the strobe light goes away for a few seconds when the engine dies then reappears when it catches again.

I am beginning to think my problem is somewhere in the distributor but am at a loss on how to troubleshoot it.


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## harry16 (Dec 8, 2011)

Ernie,

The timing light stops because the spark stops.


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## harry16 (Dec 8, 2011)

I remember an intermittent problem like this on my neighbor's Ford tractor. Turned out to be a bad connection on the key switch. To eliminate this possibility run a hot wire direct from the battery hot to the coil input.


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## mandoman (Apr 26, 2016)

*Have you checked the insulator?*

I hate to beat a dead horse but once again have you physically removed and checked the insulator that goes through the dist. housing. This is a problem area! 

Temporarily jumping the hot wire on the coil from the bat. will certainly eliminate any problems on the ignition switch side, however it WILL NOT solve a shorted wire or terminal going through the dist. housing. 

If you aren't careful you will have the new plugs ruined again, and the tractor will not start at all once again. 

I would spend ten minutes and check the insulator just for assurance reasons.


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## ErnieChilton (Jul 25, 2014)

I’m willing to beat a dead horse or anything else if it will help me solve this problem. I have placed a jumper from the battery to the coil just to make sure it is not a switch problem. I replaced the ignition switch with a spst toggle during the rebuild. I suppose the voltage kickback when the points open could cause arcing, but I have used these switched as kill switches on Vertex magnetos for years and have not had a problem with them. I have examined the connection to the distributor and didn’t see any evidence of arcing. Ohm-meter checks are good, but again, this is a static check and the kickback could still cause a problem. The rotor does have a small amount of play on the shaft but I cannot tell if this is caused by a sloppy fit or play in the vacuum advance. Both the original and replacement rotors fit the same and I checked to make sure the spring clip is on the shaft.

Now here is a thought that puzzles me. I have always been concerned about the alignment of the rotor tip with the #1 post when the engine is timed at 4 deg BTDC but finally decided it was OK. It is hard to tell exactly how well it aligns because the dust cover conceals the rotor but as best I can tell, the leading edge of the rotor tip is barely touching the post. The rotor is turning clockwise so if the centrifugal advance is working right, it changes the relationship of the rotor tip to post and should move the rotor tip farther on the post. The advance should be 13 deg at 1200 rpm and 24 at 2200 rpm. If the rotor stops touching the post when it advances the timing, the spark will go away and would cause the problem, but I don’t see how this could happen. I have tried moving the distributor gear forward and backward 1 tooth before (see original post), but I cannot get the engine timed in either of those positions. Besides the engine ran good at 1200 rpm before I began having the problem.

My next move is to remove the distributor and go through it completely to see if I can find anything wrong. If I find nothing, I will just buy a new distributor. I might have enough spare parts left over to build another engine when this is over.


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## gman51 (Mar 22, 2016)

If the timing light quit flashing then no doubt your coil or distributor quit functioning. It could be losing its ground or like others said it could be grounding out the + side or the coil is losing the electrical feed. I think the poor spark is causing the plugs to foul which is why the black smoke before it quits running.
I had a Ford 302 that would bang out around 3600 rpm and I thought it might have had an rev limiter on it. I changed the distributor out with an HEI unit. No more banging out. Evidently the old coil was breaking down at the higher rpm.
I do believe you have an ignition problem. Now you need find where the problem cause is.


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## ErnieChilton (Jul 25, 2014)

Well, I just chased another rabbit down a hole. I was so enamored with the centrifugal advance theory of the spark disappearing when the rpm picked up that I lost sight of the facts. Namely that the advance mechanism has no bearing on the rotor tip to the distributor relationship. The advance mechanism advances the breaker cam on the shaft but the rotor’s position is constant. 

I checked the electrical connections and they are all good. Then I did an ohm meter check for continuity between the #1 distributor post and the coil post with the engine timed at 4 deg BTDC. There was no continuity. I previously guessed the leading edge of the tip was pointed to the #1 post by eyeballing the rotor tip positioning. It’s close but not making actual contact. There is a little play in the rotor that I could not get out and I guess this could be enough cause the problem. Why it will crank and start is surprising. I suppose the rotor is close enough to arc over to the post and start but resulting in a weak spark at the plug. I previously tried advancing and retarding the distributor 1 tooth in both directions without any results but was probably also fighting fowled plugs at that point. I also ordered a new spring clip to see if I can tighten the rotor on the shaft.

My next step is to try repositioning the distributor gear 1 tooth to see if I can get the rotor to make contact. It is always fun to reposition the distributor because you have to completely pull it out and turn the hex drive shaft to align with the socket in the end of the shaft, then try to get it to engage again just 1 tooth off.


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## FredM (Nov 18, 2015)

the tip of the rotor has an air gap between the rotor tip and the distributor cap poles.

is the tail that goes from the distributor insulator to the cam plate original ??, I have come across a problem from constant moving of the plate to cause the copper wiring to come apart and when the engine starts to rev causes misfiring and all sorts of crap, I went through the same as you, replaced HT leads, plugs, points, condenser, new distributer cap, and weeks later decided to check out the tail, sure enough, the copper wiring had fractured, replaced the tail and there it was, just a thought.


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## Aircommuter (Jun 12, 2016)

The firing order you are using is correct for the old fords. That is determined by the crankshaft design, either number one journal is in the sam plane with number three or number four and that gives you that unusual firing order. I have just one dumb question, is the firing order following the correct distributor rotation? 
How is the condenser? You can't leave anything out at this point.


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## ErnieChilton (Jul 25, 2014)

Well, another rabbit hole has been eliminated. If there is supposed to be an air gap between the leading edge of the rotor and the post, then my continuity check was useless. The rotor is turning clockwise and pointing toward the #1 post but obviously with a small air gap. One thing has always puzzled me is a #1 marking on the rotor cap. I cannot get the rotor to point to that terminal no matter how I position the distributor. However, the posts are evenly spaced on the cap, as long as the rotor is pointing to the terminal connected to cyl #1 when it is timed at 4 deg BTDC, it should be fine. All the other wires are connected in a clockwise 2-4-3 order. Remember the engine originally ran fine @ 1200 rpm with this configuration, just would not idle. Now it cranks and runs at low speed for a short 10-25 sec but the spark goes away when it starts to pick up speed. This cycle will repeat for a couple of minutes until it finally dies.

The distributor seems to be working ok. The centrifugal advance is free and moves the cam lobe on shaft. The breaker plate on a centrifugal advance is stationary and does not move like a vacuum advance distributor, so there is no movement between the distributor primary terminal and the points. I have replaced the connecting wire and checked for shorts and everything looks ok.

The points, rotor, cap, condenser are new. The coil is a 12v resistor coil which is also new. I will try replacing the condenser with another one to eliminate it. Next will be to replace the coil with another one. If these 2 steps don’t fix the problem, I will break down and spend $172 for a new distributor. After that, I will probably resort to drink.


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## cviola2005 (Feb 16, 2016)

So it just stops firing the coil when it tries to pick up speed? Sounds like too long of a dwell. Have you checked it lately?


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## FredM (Nov 18, 2015)

from trying to jog my memory, I have checked a few workshop manuals about the rotor tip in relation to distributor cap #1 post, the rotor tip should line up with the post at TDC.

does your rotor tip have an indentation in the middle of the metal tip facing outwards?, that is a center mark.

the rotor fits through the dust cap, so it is possible to mark #1 position on the dust cap.

I have to ask this question, have you removed the distributor drive gear at any time ?, could this be wrongly fitted to the shaft ?, if this was the case, this would put the distributor timing out.

with your timing light dropping out in relation to the engine stumble, I would hazard a guess that the system is briefly dropping voltage somewhere, be it the coil, condenser or wiring, if you still have the original coil, why not try that, same for the condenser, this will save you dollars while looking for the fix.

the problem will be something simple, although you might not think so.

keep at it, you will win in the end.


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## HarveyW (Sep 15, 2014)

Ernie,

In working on my neighbors Ford 2000 3 cylinder tractor, I learned that the rotor rotates CCW. Completely different engine from yours, but I assumed the rotor rotated CW. Just something to check, if you haven't already done so.


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## ErnieChilton (Jul 25, 2014)

*Suspect Distributor*

OK, here I go on a new month, the last one wasn’t so good. Didn’t get much accomplished in June because it has been hot and humid the past few weeks here. My barn is a Quonset style steel building with no ventilation except for a 16’ garage door. No matter how many fans you set up, it becomes unbearable after noon. I think it might be a little more bearable if I was making some progress.

I have been concentrating on the distributor/coil lately because the dropped spark seems to indicate a problem somewhere in that area.

1. I do not have a way to check the dwell other that verifying point gap. The cam does not appear worn and the engine ran fairly good at the beginning of this saga.

2. The rotor does turn clockwise as I can watch it when dry cranking. There is no indentation in the center of the rotor and I have marked the dust cover as best I can by marking the rotor position at TDC on the distributor housing and transferring the mark to the dust cover. However this is not a precise measurement. That is why I used an ohmmeter to check continuity between the #1 post and coil input at TDC.

3. The coil is a “person of interest” right now. It is a new 12V internal resistor coil. My old coil was 12V but used an external resistor. I have the old coil but can’t find what I did with the resistor. I could buy a new resistor but would rather just get a new internal resistor coil. That way I will have a spare coil if it does not fix the problem.

4. I did completely disassemble the distributor to check the bearings and the centrifugal advance. The gear is pressed on and a pin is pressed in to keep it in position. It is a tedious process trying to line up the holes when you press the gear on, the gear cannot be rotated easily on the shaft if there is a slight misalignment of the holes. You can get the gear to go on in 2 positions 180 deg apart. There is nothing in the manual that indicates the two positions are not symmetrical, it just says to press it on and insert the pin. Remember this engine ran fairly good at first, just would not idle. The oil pump drive shaft is a ¼” hex that fits into the bottom of the distributor shaft. The old one was worn so I replaced it with a new one made from a ¼” allen wench.

5. I have a new condenser, dust cover, rotor spring clip and internal wiring components that I am going to install and try. If that doesn’t do anything for me, then I will replace the coil. Lastly, I will break down and buy a complete new distributor.

This tractor has ceased to be a normal project, it is now PERSONAL.


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## cviola2005 (Feb 16, 2016)

I worded that wrong. Dwell is the number of degrees that the points are closed. So I should have said "sounds like dwell too short", which would mean too large of a point gap.

What is the point gap supposed to be and what is it set at? The dwell is inversely proportionate to point gap. 

Also, what spark plugs are you using and what is the gap set on them?


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## cviola2005 (Feb 16, 2016)

You said you had the plugs set at .035 and had tried .025 with same results. Did you try the Autolite 437 plugs at .025? What I'm reading elsewhere is that the Autolite 437 is the favorite plug and is usually set at .025.

Maybe the advance is grounding out the points as it turns??


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## FredM (Nov 18, 2015)

3. The coil is a “person of interest” right now. It is a new 12V internal resistor coil. My old coil was 12V but used an external resistor. I have the old coil but can’t find what I did with the resistor. I could buy a new resistor but would rather just get a new internal resistor coil. That way I will have a spare coil if it does not fix the problem.

you don't need to use a resistor with the old coil just to check the new coil out, you wont hurt anything in the ignition system, crikey mate !! give it a go.


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## ErnieChilton (Jul 25, 2014)

Halleluiah. The engine runs. 

I have finally gotten back to my original starting point. The engine runs good but still idles high.

I replaced the condenser, dust cover rotor spring clip and the electrical components connecting the points to the distributor. Had one problem, the new dust cover came with a gasket that made the cap very tight and hard to snap the retaining clips onto the cap. I found that this extra height prevented the rotor from contacting the cap coil post. Since the original setup had no gasket, I just removed the gasket. Set the points at .025 and statically timed at 4 deg BTDC. Did not help, still had the problem.

Then FredM’s “use the old coil without the resistor” jogged my memory of the cars of yesterday. They had an ignition switch that bypassed the resistor in the start position to give a hotter spark for starting. Temporarily wired the old coil in, said a few words of encouragement and hit the starter switch. Nothing, would not fire. Then I decided that it might work better if I turned on the fuel supply. Viola, the engine started and ran without dying but would not idle below 1200 rpm, ACCORDING TO THE TRACTOR TACHOMETER. I then connected my new fancy timing light and it was showing the centrifugal mechanism had advanced the timing to about 10 deg BTDC and the rpm was about 900. So much for the brand new tractor tachometer I purchased. So I still have to work on getting the idle down to the 500 rpm range. This is the same point at which I started 1-1/2 years ago!

I started looking closely at the new internal resistor coil that I replaced and noticed that the socket for the distributor wire was about 1/3 full of oil that had the consistency and smell of transformer oil. I suspect the oil inside the coil was leaking out. Don’t know exactly how this could cause the problem of starting and running then shutting down, etc., but I do know the old ignition coil solved the problem of the disappearing spark. The internal resistor coil would pull a 3/8” spark when cranking the engine over, but why it would suddenly stop for a few sec and then start again is a mystery to me. 

So now I will resume my tractor rebuilding life feeling a little humbled by this experience


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## sixbales (May 18, 2011)

Congratulations Ernie!! 

Take that tractor out and enjoy it. I don't like my diesel getting below 1000 rpm on idle.


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## FredM (Nov 18, 2015)

Crikey !!, I am happy for you mate !!, you had me scratching my head trying to figure with the cam timing and dissy timing ok and plenty of fuel, why wouldn't the sucker start, but then when I read you where losing spark when using the timing light, I thought this can only be the coil or condenser causing the problem.

Keep us informed on how you go with the idle problem.


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## PoriShamba (Jun 22, 2016)

Anyone have information on a Mcormack International 276 tractor 1975 model ?


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## gaspump (May 12, 2013)

Boy, you really have a problem!! This may sound silly- but have you good, fresh gas?


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## ErnieChilton (Jul 25, 2014)

Time for some reflections.

I can get the engine to idle around 675 rpm by turning the idle adjust all the way in which is the richest setting. This is measured using my fancy new strobe light, however the proofmeter (Ford's name for the mechanical tach) is driven directly off the hydraulic pump and the face plate has 5 rows of markings denoting the speed in mph for the 5 transmission speeds. Nothing on it indicates the rpm scale. So I really don't know which scale to read but one of them does indicate around 600 - 700 when the engine is idling. I have been assuming the top main scale was the correct one for rpm since it ranges from 0 to 2400. Right now, this is a minor problem which I will deal with later.

The plugs still show a rich condition that I cannot correct using the main needle. Probably because the idle mixture is set at max position. One of my local buddies told me that some of the new rebuild kits had main nozzles that were slightly larger that the original ones. I will find my old nozzle and compare it to the new one to check that possibility.

However it has become more fun to work on the tractor now that the engine runs pretty good considering history.

Right now I am working on cleaning the fuel tank so I can get rid of the Folgers Coffee Can version. Have poured 3 gal of vinegar along with a handful of square nuts in it and strapped it to a rear tire on my Mahindra. Plan to do some bush hogging for a couple of days to clean the rust out.


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## ErnieChilton (Jul 25, 2014)

Since my last post I have gotten the engine to idle smoothly between 700-800 rpm with the original TSX. Even though I have been working on this engine for well over a year, it still has not run enough to be broken in, so I expect it will idle lower as I get more time on it.

I have been trying to figure out how the situation deteriorated . First, the TSX carb was badly rusted and I couldn’t get the idle jet out. Since it ran good above 1200 rpm, I did not worry too much. Then I started to screw with it. By the time I got around to trying the new Zenith carb, I think I had fouled the plugs. Then when I switched back to the TSX, it would not run smoothly at any rpm. I then drilled out the old idle jet in the TSX, retapped it and installed a new idle jet. Since the plugs were now fouled, it had the same problem as the Zenith. Hence my excursion into the distributor and timing. Sometime during this process, the brand new coil started exhibiting its problem, good spark at low crank speed but no spark when the rpm picked up. When I finally tried new plugs, I still had the coil problem. Then replaced the condenser and all distributor electrical connections. When I finally managed to get the engine to run long enough to get a timing light on it, I found the spark disappeared when the engine started to pick up speed. Only when FredM posted “You idiot, try the old coil” (but in more diplomatic language) did I finally have all good components and the engine runs smoothly. There’s a lesson in there somewhere.

I have now cleaned the gas tank, replaced my old dependable Folger’s coffee container and can move the tractor in/out of the barn to finish sandblasting the rear half. The only problem being that, at this time of the year in Alabama, the humidity is so high. You can’t sandblast with wet sand!

I will now resume my posts to the Ford Forum, since any problems I have will be Ford related and not be engine related (I hope). Thanks to all of you guys out there who stuck with me throughout my trials and tribulations


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