lx178

[mowerguy88]

hey guys looking for some knowledge. ive got a jd lx178 on the bench with a kawasaki liquid cooled engine that has a cdi ingition system. i have a service manual for it and have performed the testing procedures. in the manual it says if the part tests fine but still doesnt work to replace with known good one. well i dont have another machine or parts to do that with. and i dont want to fire the parts cannon at this unit because its old and the customer doesnt want to put alot of money into it. when i start it up after sitting it will fire right up and run great for about a minute then it shuts down like your turning off the key. check spark and i have none. let it sit an hour or so check spark and it has spark but its very very weak. same deal, it will start and run for a min then shut off and spark is gone. does anyone know about these machines? more specific the cdi ignition on them? dealing with three wheelers and the like in the past 9 times out of 10 a condition like this is usually a bad module, brain, etc what ever you want to call it. john deere calls it an ignitor. and info would be appreciated.

 

[hacskaroly]

I wonder if something on the spark train warms up as it starts and gets to the point that it expands to the point where metal is touching or spread apart too far to keep the spark going and when it cools, it is closer to where it should be and can start back up again. On a chainsaw I would guess it would be a coil issue or a coil/flywheel gap.

PS, welcome to the forum!!

 

[EFSM]

Does that have a little silver one-pronged igniter? It should be on the side of the engine. That could be bad.

 

[mowerguy88]

Does that have a little silver one-pronged igniter? It should be on the side of the engine. That could be bad.

It does have an igniter. It’s a black box with 2 pigtails coming out of it. That’s what I’m also suspecting just wish I could pinpoint it further

 

[mowerguy88]

i did swap the ignitor with a brand new oem unit and it does the same exact thing. ive also tried new coils. the coils were aftermarket but same thing.

 

[EFSM]

Is this a single cylinder engine and what model engine?

 

[mowerguy88]

2 cylinder fd440v kawasaki

 

[Likesaws]

Just a thought did you check for loose ground connections?

 

[EFSM]

Could you post a picture of the igniter? Most of the FD engines have a 12v supplied ignition without an igniter. FC series is the only one I can think of with an igniter like I was talking about, but this may be a really old FD with a similar setup.

 

[mowerguy88]

Just a thought did you check for loose ground connections?

Yes I did

 

[mowerguy88]

Could you post a picture of the igniter? Most of the FD engines have a 12v supplied ignition without an igniter. FC series is the only one I can think of with an igniter like I was talking about, but this may be a really old FD with a similar setup.

 

[EFSM]

That’s older than any FD I’ve ever worked on. What a weird setup!
I would suspect supply voltage to the igniter. I’m sure it has a 12v feed wire somewhere. Find a mower wiring diagram and do some testing.