JD LX 188 carb

super99

Well-known Member
My LX188 wants to start and dies right away. Acts like you turned the key off. I put a spark plug tester on a plug, and it fires until it stops tuning over. I was thinking the shut off solenoid might be the problem. I asked at the JD dealer and was told to cut the tip of the solenoid off, all it does is keep it from running on after you turn the key off. Is this correct? Thanks, Chris
 
If you're loseing spark when you release ign sw from start to run position the most likely cause is a bad/loose connector on ign sw,bad ign sw,bad relay or a problem in safety sw's/wiring harness on tractor,the fuel sol on carb has nothing to do with ign system on eng.
 
As far as sol on carb dealer is correct about function of same it prevents run-on & eng backfiring when you turn ign sw to stop position.

To help isolate problem,remove air filter on carb,have someone sit on tractor & crank eng,when eng fires in start position & key released to run position put a shot of carb cleaner/starting fluid or gas into carb,if eng continues to run then problem could be in ign sw,wiring harness on tractor or sol bad/plunger stuck in same due to rust/dirt.


If eng dies when releaseing ign sw & shooting carb cleaner/starting fluid or gas into carb makes no difference then problem in ign system possibly caused by loose connections at ign sw,bad ign sw or a bad safety sw on tractor.
 
You can test the fuel solenoid circuit with a test light, probe the connector, see if you get power to the solenoid when cranking. If the safetys are satisfied, you should continue to get power once the engine starts.

I found a wiring diagram on bing images search. What a mess! Tried to copy/paste, wouldn't work.

I would recheck all your safetys, brake switch, seat switch, PTO's, and interlock module(?). All these appear to be able to shut down the engine. There are also a couple of fuses, and way too many diodes!

Look for the obvious, fuses, something unplugged, a safety switch not working...

Good luck!
 
I can't remember which engine is on that mower.

It is common for the plunger in the fuel solenoid to stick and refuse to function. I have seen a couple with a rubber tip on them where the tip actually came off and was moving on its own to stop the fuel flow. I have also seen some that would close when hot. Just checking the continuity in the solenoid winding and the circuit for it does not tell the whole story.

Your dealer may not be giving you the best advice about cutting the tip off the plunger. Its on there in attempt to prevent backfire when the engine is turned off. Backfire when the engine is stopped is an uncontrolled explosion and tends to blow head gaskets. I am also told it can warp exhaust valves, but I have never witnessed this.

On the other hand it may be in his best interest to tell you to do this, if he can sell you a head gasket on down the road.
 
Thanks for the reply's. I'm pretty sure it's a fuel issue. When I start it with the spark plug tester installed, it lights up as long as the engine is turning. It starts and dies, the motor keeps turning for several revolutions, and the plug tester keeps lighting up until the revolutions stop. I haven't tried pouring a flammable liquid in the carb when it dies yet, but I'll try it the next time I get to work on it. I took the gas line off of the carb and tried the fuel pump. It doesn't pump a solid stream, it will pump good for several seconds and then slow down for a second or so and then pick back up. Looks like it should pump enough fuel to keep the bowl full tho.It's an old mower, all the safety switches have been bypassed by the previous owner. Thanks, Chris
 

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