John Deere LX176 backfires, won't start

[xp14629]

Check to see if this engine has an ignitor on it. It is what controls the fine tuning of the spark timing. Like what a cars computer uses the crank and cam sensors to do. If it goes bad, you can have perfect spark but could be off a few degrees and backfire or off a lot more and only crank over. That could also explain the black plug, late or early spark will be the same as a weak spark.

 

[xp14629]

It will have a single spade terminal on the bottom with one wire going to it. The unit itself is only about an inch square and a quarter inch think. It would be mounted on the engine shroud providing the ground.

 

[Rivets]

Don't know how handy you are, but pulling the flywheel is not that hard. Once you have the nut off screw it back on until it it just flush with t.he end of the crank. Now if you have a buddy it will help. Take two large screwdrivers and pry up on the flywheel. Careful that you have a good solid pry points. Strike down hard on the nut and crank squarely with a big hammer. IF YOU DO NOT HIT IT SQUARELY YOU COULD DAMAGE THE CRANK. BIG $$$$$$ IF YOU DAMAGE THE THREADS. It should pop loose. If you are not comfortable doing this, don't try. Also, if you do find a parochially sheared key buy a new one, don't try to make a new one!! Don't forget to torque the nut when you reassemble or you will shear the key when you try to start the engine.

 

[LilJayV10]

I appreciate everyones replies. I pulled the flywheel off tonight and the key is not damaged. However the entire underside of the flywheel is incased in dirt. It's caked on. It fills the gap between the inside of the flywheel to the pickup thats bolted to the engine block.

It can't be helping anything but do you think it would cause my problem? Is there anything I should check while the flywheel is off.

Also what is the torque spec for the flywheel nut?

 

[Rivets]

I believe the torque is 45 foot pounds. Does your carb have a fuel shut off on the bottom of the carb? If it does, take it out and check it. How? Attach the wire the positive terminal of a power source and touch the negative to the case. You should see the shut off close.

 

[LilJayV10]

I got it back together and it started. I thought I had fixed it. Let it run for about 15 minutes and it wouldn't restart. I shot some starting fluid in it and it wouldn't fire. Iced the module down on the side of the engine and it fired up. I mowed with it for about an hour. Shut it off and it wouldn't restart. Going to try and ice the module down again here in a bit.

I'm having an issue with the hydrostatic drive. I will probably have to start another thread about that.

 

[LilJayV10]

Actually I think I just need to replace the belt that goes to the hydrostatic unit. It's wore out. It starts slipping when you go up a hill or try to press the accelerator all the way down. It will move fine as long as you don't press the accelerator down too far.

 

[LilJayV10]

I checked the fuel shut off like you suggested. After it ran for a while, then wouldn't restart I checked the plug. It was dry. It's getting spark but when I shot starting fluid in it, it wouldn't start either.

When it does start it runs great. Is there anything besides the module I should be looking at? I don't know if I have/had more than one problem or not.

 

[cityfarmer]

did you ever get this fixed? if so what was the cause. i seem to have the same problem.
when i shut it down it backfired, has not started since, using charger in start mode it can try starting it till the cows come home , tried starting fluid, check fuel filter.

backfires when i vary the throttle during starting procedure.

 

[pawl]

it would be nice if some one would finish this post. there is no answer as to what the problem was. I am having the same problem. almost certain it is an electrical problem. it will start and keeps running well ocasionally but mostly just turns over and backfires. I have done every thing this dude has done and it just turns over. maybe its just a piece of junk like every other vehicle:frown: with computers and circuit boards on them. :frown: