# 8N Engine Performance Problem?



## MarkS-Mich (Jul 12, 2004)

Hello,
I am wondering if my 1950 8N 1950 is running to full engine power. It seems to dog, even w/o pulling the mower or running the PTO. It really bogs down with the 5’ mower. Symptoms:
- Little bit of misfiring, but not much
- Acts like muffler is plugged, but I have ran w/o muffler
- Reminds me of worn cam shaft, but I have no reason to believe there is a bad cam in my 8N.
- There is a slight, “lifter knock” towards the front cylinders (#1 or #2)
- The engine revs up from idle to wide open throttle real well, and does not stall, is easy to start, and idles well. There is no sputtering during rev up or down – engine tracks well to accelerator lever. 
- I did notice the governor is a little loud (gear noise), but perhaps that is normal.
- It runs pretty well in 4th gear, but just seems like it is starved for fuel or air. 
- Almost acts like it is running on 3 cyl, but all seem to be running – checked by pulling spark plug wire.
I am not really sure how these things are supposed to run. What I have done/checked:
-	Cleaned air filter completely. No blockages in air supply tubes.
-	Put in & gapped new spark plugs (spark seems OK).
-	Spark timing – check and tweaked 1 deg. using timing light on flywheel. Set to service manual: 4 deg. at 400 RPM, 10 deg. at 1200 RPM, and so on. Distributor cap, rotor, points and condenser all look new – did not check points gap yet.
-	Coil seems OK, but may be older. Tractor is 12v converted but seems to be OK – not sure if right resistor, just assuming it is OK, no other obvious reason that electrical is not working OK. Possible weak coil or wrong resistor? 
-	Cleaned sediment bowl, and fuel screen at inlet to carb. Removing fuel line at carb. allows fuel to run out of line freely.
-	Adjusted idle air screw on carb. Adjusted main jet screw by cranking clockwise until engine dies out then back off 1-2 turns CCW. More CCW does not seem to have any affect. Not really sure how properly adjust either idle mixture or main jet – just cranked closed until engine dies out , for either, then back off a turn or two.
-	Governor seems to be OK , and butterfly throttle plate seems to open OK, and governor linkage look OK. About governor: In addition to the slightly more than I would expect gear noise (but that could be normal ?), the proofmeter runs “pegged” to max at about 1000 real RPMs. Not sure if this means a bad proof meter – runs with cordless drill OK, or bad governor. Proofmeter cable seems OK. I bring this up for two reasons, 1) why proofmeter is not working correctly? and 2) because it may be relevant to engine performance problem. External tachometer shat that max RPM is about 2200-2400.
-	Compression check: 90 PSI on two of the cyl., 100 PSI on a 3rd one, and 105 PSI on another. So I think piston rings are OK.
-	Fresh GL-1 in trans, but not sure if that would matter
-	Fresh gas
-	Choke is all the way in, and I think, but have not check that choke plate is all the way open. On that note, engine runs almost like choke is on about ¼ - just enough to starve it a bit for air.
Things I have NOT checked:
-	Run tractor, briefly, w/o air cleaner, by unhooking at carb.
-	Check points gap.
-	Check for possible weak coil – not sure how to.
-	Replace plug wires, points, condenser, distributor cap, even though they look new, just to eliminate them – (new plugs last month).
-	Possible sticking valve(s). Not sure how to check. Manual says something about dumping some kind of cleaner in carb, while running at medium to high RPMs.
-	Worn cam shaft or lifters – not sure how to check w/o pulling head off?
-	Balast resistor – I have no reason to believe that anything is wrong with electrical.
-	Have not torn apart carb. Possible gum in carb? Does the bowl collect sediment? Probably should check choke system.
Summary: the engine seems to be acting restricted, either on air or fuel. But it acts more like air flow problem, as if air or intake or exhaust are restricted, either by the air cleaner, valves or exhaust.
Any tips or about this engine problem and how to know what “Henry the 8” should run like would be greatly appreciated. 
Just for reference: 8N-B block with side mounted distributor.
Thanks in advance.


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## psrumors (Apr 25, 2004)

*MarkS*

Welcome to the forum. If I can't answer your question someone will be along that can.

I say governor. Why? Because I have never heard mine. I have never heard any governor on any N series ford make any noise.

The sympton of the tractor running good under no load but bogging with the 5' mower points to governor. The only thing that doesn't is the tractor running good in 4th gear.

Check the governer. If that's not it (90% sure it is) clean the carb.


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## Ingersoll444 (Sep 17, 2003)

Well My 8N is still kinda new to me, and is a bit beat, but I have NEVER heard a sound from the gov.plus if the PM works with a drill on the cable, it should being driven by the gov. Somethings wrong here. 

Granted could be another problem also, just sounds like the gov's bad.


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## MarkS-Mich (Jul 12, 2004)

*To the moderator*

I was in the process of posting a lengthly reply about the governor and listening to the engine sounds via the hood, did a spell check then hit submit. The web page told me I was not logged in and so when I logged in, the message was gone. Was I some how logged out while in process of typing, since I was on same page for like 10-15 minutes? Did my reply go into cyberspace?


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## parts man (Sep 24, 2003)

Mark,, yup. Sorry, afraid that can happen. The site recognizes you as you load pages, if you don't load anything new after a certain time, it assumes you are not here any longer.
In the future, for long posts, if you type it in word or some thing similar first, you can cut and paste so you are not "inactive" for as long a period of time.


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## tomttomtom (Dec 24, 2003)

Seems like with everything you've replaced it'd run great!!! Did you by chance miss the firing order 1243


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## dove (Jun 12, 2004)

Mark
Let me share with you my two cents worth. Awhile back I took my 1950 N down for some engine work and a paint job. When I put it back together I got the wires reversed on the coil. It had exactly the same symptoms you described. If your tractor is a negative ground then then the negative side of the coil goes to the distributor. Just something to check.
Dove


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