# Craftsman LT1000 major problems with starting and running



## Tina B (Jun 11, 2018)

I am not a mechanic, but I am learning the hard way here due to limited income. BTW, this is a Briggs & Stratton engine, with Nikki carb. 

I'm at a loss. Here's how it all began. The mower was running fine. The steering geer assembly was going bad and finally I could not turn the wheel without extreme effort, so my Dad helped me remove the old one and replace with a new one.

He suggested tipping the mower on it's side to access the assembly, which we did. Said he had done that many times to do repairs.
It stayed on it's side until the new assembly came in. We installed it and uprighted the mower. I could not get it to start after that and discovered it was due to the oil filling areas it wasn't supposed to. The spark plug was swimming in oil. I blew the oil out, using the method I was told to do by removing the plug and turning key to start. Yep, it blew out lots of oil. I cleaned the plug off, and put it back in. Then added oil to the full line on the dipstick. The mower started, smoked like crazy for a few minutes burning off that oil residue, and then it was running good. I mowed the front and back yard with no real problem. A few days later, I tried to run it but after a few minutes of running it would die out. Then it decided to not start at all. I tested the fuel solenoid, and it was reacting exactly as it should. The carburetor bowl had gas in it, but it acted as if it wasn't getting gas at all. I ordered a new solenoid, because my Dad thought it might still be a problem based on the symptoms, installed it and still no start. Turned over fine, but no start. 
I removed the carburetor, cleaned it...everything looked good there, reinstalled it and still no start. Just in case something was still wrong with that, I ordered a new carburetor kit that came with new plug, gas filter, air filter and shut off valve etc. It was not a nikki carb, it is an after market brand. Installed the new carb, plug, changed the oil and oil filter, new fuel filter, and new gas line. (I'm sure I'm missing something else I did) Basically everything new. The old oil smelled like gas, so there was certainly some gas in the oil. Probably from that tipping on it's side thing?
After installing everything it started right up. YEY...however it had a really fast idle, and I was not able to run the engine at full throttle. Every time I would go full throttle position it would immediately try to die out. So, I mowed the lawns (fields at this point) at half throttle where it would work. Just as I was finishing up, after about a half hour, the engine started missing and surging and acting like it wasn't getting gas again. Plenty of gas in the tank. I took off the gas cap and inspected it for plug ups, and there is no issue with the venting. I shut the mower down, and came back out a few minutes later to start it and it ran very rough and I couldn't get any leveling out or throttle up. So, I'm thinking this aftermarket carb might have issues.... 

The old carburetor had gotten another cleaning from a relative and he said it was clear and good to go. SO, I took off the new carb...put the old one back on and it started, but it runs very very rough like it doesn't want to run at all, and has now started smoking out the front. Appears to be white smoke. It will not idle, when I put the throttle at the idle position it dies. The intake gasket seems fine, so I don't see a vacuum leak being an issue...but I'm not sure.

What do I do next?? Forgive me if some of my questions seem uneducated, but in the realm of lawn mower engines, I am limited in my knowledge.

Could this be a spark plug gapping issue with it having a brand new plug? Do plugs have to be gapped when they are new, or are they factory set? Can that cause it to run so rough, smoke, and not get full throttle ability?

Is it possibly still an issue with the solenoid, can that cause it to run so rough and smoke? The old one is on it currently. My understanding of the fuel solenoid is that it designed to stop the gas from entering the carb after shut down, and to prevent backfiring.

This is driving me bonkers. Please don't scold me on the mower getting tipped on it's side, I realize now I should have questioned that method. What's done is done, and I can't go back and correct that decision. ;-) Any advice, direction or methods to try are truly welcomed and much appreciated. I cannot afford to pay to have this diagnosed and repaired, the last of my funds went for that new carb. If I can do it myself, I will. Tools aplenty, and tons of patience. I am not afraid of grease, oil, dirt, gas or hard work.


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## sixbales (May 18, 2011)

Howdy Tina, welcome to the tractor forum.

Not to worry, we've all tipped an engine on its side and discovered the same as your experience. Some engines will tolerate tipping and some will not. It's best not to tip them very far. 

My luck with cleaning old carburetors has not been good. I would put the new carburetor back on it. Get it running and try adjusting the jets. Mark the original jet position so you can always return to that setting if you screw up. It shouldn't take much adjustment to get it running well. Make sure your throttle linkage is free to move. A balky linkage can cause problems.

This forum has some excellent small engine gurus. Hopefully, some of them will chime in and get you going.


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## FredM (Nov 18, 2015)

Hi Tina, good to hear you are having a go, do you have a service manual for your mower?, can you tell us what the engine model and HP size is too?, When you filled the fuel tank, was this new fuel or old ?, new plugs should be gap checked before use for the engine specified, have you had this mower long ?.

Best to lift the front of the mower up with an endless chain and stand it on its rear to work underneath, before doing so, place a plastic bag around the filler neck and screw the cap back on tight to stop fuel leak, doing this may not be suitable for you though.

Reading and re-reading, I feel you may have moisture or bad fuel and that will cause the spitting etc. as quoted in your post, if the fuel is good, we will go to the electrics and check for spark quality, and even check the valve clearances if you are up to it, we need a service manual and if you can supply the engine info I mentioned earlier, I will do a Google search for an online manual that you can download if you haven't already got one.


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## jhngardner367 (Apr 5, 2011)

*Welcome to the forum,Tina,
It sounds as if the muffler may have gotten flooded with oil/fuel,when it was tipped.
This causes the engine to be unable to breathe properly,since there's no way for the exhaust to exit,properly.
remove the muffler(not the exhaust pipes,though),and try to run it.
If it clears up,the solution is: put the muffler in a small bonfire,on its side,to burn the excess oil/fuel out.....or,replace the muffler.
You may,also want to check the crankcase breather valve,to see ifit's plugged.
It's a small plate with a tube that goes to the valve cover,or air filter assembly.
Also ,could you post the model number,of the tractor?
It should be on a label, under the seat.
That will help ,in finding the model of the Engine used,if the engine numbers aren't stamped on a valve cover*


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## Tina B (Jun 11, 2018)

Thank you all for your responses! I've had this mower for many years, I think I bought it somewhere around 2004 new. It has done well for me. I do have a manual, and it has been extremely helpful in locating parts and getting part numbers. It's an owners' manual, not a real service manual like a vehicle would have for technicians and mechanics.

My engine model number is 31H777, TYPE NUMBER 0297-E1
The nikki carburetor model is 698445.
The tractor model number is 917.273402

The gas I put back into the tank was fresh, as well as the oil and oil filter, so nothing old was going in. I did a test on the gas cap venting this morning, even though I had inspected it and found nothing wrong, so I increased the throttle to the point of cutting out on the engine and loosened the cap. It did not help and the engine eventually died.

The idea of oil being in the muffler makes sense, so tomorrow I'll check into that. Also, the crankcase breather valve. There might be a small hole in that tube, it felt odd when I attached it back on. I'll inspect that closely. I'm not sure what it will take to remove that and the plate, but I will venture into that tomorrow too.

On the new carburetor, there were several complaints on Amazon from buyers that they could not adjust it. Several stated that trying to adjust had no effect on things at all. I wasn't sure if they were novice and not understanding what they were doing or not. The majority of the feedback were good comments. So, if I can't get the old one going correctly again, I'll put the new one on and try again. Or.....use new parts on the old one? There is a small rubber o ring inside that carburetor that the plastic float seats into, (I hope you understand that) it had become smashed on part of it and it is misshaped now. I'll post a pic of that tomorrow to show what I mean.

The fuel solenoid....opinions while testing things out were that the old one was not operating properly and I ordered a new one but not an OEM. The new carburetor also came with one. I tried the brand new one in the old carburetor and it would not start. Put the old one back on and it started. Then I tried the new one that came with the new carb, again...no start. Turns over, but no start. Put the old back on and it started. I'm told that if these are faulty, sometimes you can start okay but once the engine warms up a few minutes it will die. This did happen. Is this a possibility that the solenoid is actually bad too?

Tomorrow I will get greasy and oily and post my findings and/or results.

Thanks again everyone, it's great to have knowledgeable help out there from experience. 

EDIT: A little more information. Before I left for work this morning, I pulled the new plug out. It was completely carboned up. Black...black black. Can this be cleaned? I need to find my spark plug gapper. I know I have one...somewhere in that garage. LOL


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## Tina B (Jun 11, 2018)

That little rubber O ring is quite an important part
it appears. It is the fuel inlet O ring, and if damaged can cause issues like flooding, I'm told. I'm going to replace that today, and I'm heading out to test the choke as well shortly.


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## Tina B (Jun 11, 2018)

I have tested the choke. I took off the air intake and watched as I started it. The choke was open. Ran beautiful, idled perfectly...right up until I tried throttle up to the point that the choke arm was pushed by the linkage. As soon as that butterfly started to close, the engine started to die. I immediately went back down to idle speed, it opened and spit a little gas and white vapor came out. After a few seconds the engine leveled out at idle. I reattached the air intake and filter and let it run for about ten minutes at idle. No overheating issues, no smoke and smooth idle. I tried to throttle up again and as soon as that choke lever started to turn it tried to die. So there be the problem. What do I do to correct that? Thanks a bunch! Oh, what I thought might be a hole in the breather tube was just some manufacturer dots of some kind. No holes there.

EDIT: Okay, this is so simple it hurts. LOL I sat down to think this through on how this is operating. The owners MANUAL says to run the mower in the fast position. Fast position shown in the manual is the running rabbit icon at the top of the throttle control lever guide. (makes sense, fast rabbit for fast running) Idle is the turtle at the bottom. Quoting the manual: "Always operate engine at full throttle. Operating engine at less than full throttle reduces the battery charging rate. Full throttle offers the best bagging and mower performance". And: "When engine starts, move the throttle control to the fast position." Fast position in the manual is the rabbit.

This is what has been going wrong, it appears the rabbit position is the choke (the lever will not go any higher than the rabbit icon position) and running position should be lower down where there is a notch on the side. The choke icon is well above and off to the left of the throttle guide opening. So when I put the throttle lever to the rabbit position, it is actually operating the choke. I can barely see the rabbit and the turtle, they have almost worn off comepletely...but it's there.
I've always run the mower at the notch, I guess because it made sense to me. Never until now referred to the manual on that. Never really thought about the choke, because I had never really needed it. 

Grrr...... The mower runs great at the midway point where the notch is. So far. Now that the choke lever has been fixed, (it wasn't springing back before) I shouldn't have any issues. We'll see. Do you see how that could have been confusing? I'll report back after I try to mow the front yard for a second pass.

I have learned way too much about chokes and rabbits today. ROFL


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## Tina B (Jun 11, 2018)

Just a note: This mower did have problems with starting and running in general after that tipping and oil going everywhere, the choke lever was not working at all, so the work would have to have been done anyway. I just wish someone would have figured out that rabbit and choke area before all this headache.


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## Tina B (Jun 11, 2018)

Reporting back. Despite all of the above, the mower will not run at full load. I cannot even throttle up to the notch (halfway point on throttle lever) without it dying. Once I engage the blades and try to move it, it chokes out and dies. So, I'm taking the old carburetor off then putting the new one on again. I'll inspect the old carb. I have already removed the old carb and the bowl was full of gas.














Here's a couple of pictures of the O ring I was talking about, it appears to be smashed and out of shape:


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## Tina B (Jun 11, 2018)

Okay, my brother stopped over after work to look at this. The new carburetor is on it. He checked things over and looked at the flywheel. He didn't think there was any gap between the flywheel and the spark plug terminal, so he loosened it up to gap it like it's supposed to be.Without the hood or shroud on, he ran it and mowed with it. It seemed to do just fine. After that he adjusted the idle and mix on the carburetor to run smoother and that seemed to work fine. Did not test it when mowing after that. He saw there was a bolt missing that holds the part that houses the dipstick and installed a bolt. Then put the shroud and air cleaner etc. back on. One problem with that. The shroud was put on around that dipstick housing incorrectly. When I went out later to run the mower, it was making a nasty new noise in addition to rough running. I shut it down immediately, took the shroud off and discovered the dipstick housing had been pressed against the fan on top of the flywheel, thereby the fan was cutting into it and wound up flattening out the top edge of each plastic fan blade.
No real issue at this moment but I will have to replace that.

When I ran it, it started the same thing with the running rough. I was able to engage the blades and mow some grass but I could hear the carburetor popping and engine missing. I could not run it in the notched, "fast" position without it getting worse.

Is this a simple adjustment on the carb to be done again because it's running too rich? When the fuel mix was adjusted he had to back that adjustment screw almost all the way out to get it to run smooth. He says to turn it another quarter turn and see if it helps. I'm done with this for today, I'll get to it again this weekend or one morning before that. Any suggestions, ideas, knowledge...throw it at me!


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## Tina B (Jun 11, 2018)

SOLVED

Just in case anyone reads this thread to see the solution, I have finally got my mower running smooth. Turns out that brand new aftermarket carburetor was junk. The mixture screw would not have any effect at all on it. I got nothing but popping, spitting, rough running, and could not run at full load at all no matter how I adjusted that. Once I engaged those blades and tried to move it would pop and try to quit.

I almost decided to junk the mower, but gave it one last shot. I ordered a carburetor rebuild kit, and cleaned/ rebuilt the old carburetor with the new components and gaskets. Installed it on the mower, and even without adjusting anything I had an immediate start up with no pops, smoke, spits, or missing. I was able to throttle up to full speed and it didn't even hiccup. Then I tested it by mowing the back yard. Took about a half hour and did great. I think it sounds better than ever. LOL

So, just for the heck of it I took apart that new carburetor. I had to know what the differences could have been. Everything seemed the same except......the gasket that seats on top of the float was apparently not installed correctly. It was smashed and damaged on the outer ring and one of the inner loop areas. It did not fit in there the way it supposed to, not sealed properly at all. Hmmmm.....

I won't be buying any aftermarket carbs again. I'll stick with OEM whenever possible. That goes for the cheapy brand fuel solenoid, (I think it was around $8.00, the OEM was $47.00) the brand new one would not allow a start. The old one (OEM) works perfectly.

Thanks for ideas here and I hope this is the end of that fiasco.


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## jhngardner367 (Apr 5, 2011)

I would send the new one back,and demand a refund.


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