540 JD not starting when hot

rockwall · January 18, 2014, 02:41:44 PM

I have a friend who has a 540 and is having trouble with it starting when it has been running for a while. He says it runs great otherwise. What's up?

snowstorm · January 18, 2014, 03:38:50 PM

low compression. get someone to test it

SliverPicker · January 18, 2014, 03:50:49 PM

Bad coil. Put a meter across the terminals (wires disconnected) in Amp mode. Tap coil with a screw driver handle. If reading jumps around the winding is bad. If this test shows no results try swapping in a different coil that is known to be good.

duckslayingpro · January 18, 2014, 05:07:33 PM

Unless he has swapped it with a gas motor it will not have coils. If it is a gas engine that would be a good place to start.
does it turn over alot slower after it is warmed up? If so it is the hydralics locking the motor down. I know this sounds stupid but if it is turning over slower jerk the steering wheel left to right vigourly while cranking motor and it will start. It will be relieving the hydralic pressure.

loggah · January 18, 2014, 05:17:11 PM

My guess is a bad fuel injection pump !!! i had the same problem in my John Deere feller buncher,started fine when cold,and when it was warm it wouldn't start,when the engine cooled off it would start fine again.The heat from the engine changed the tolerances enough in a warm pump so it wouldn't build pressure. Have him put some snow or cold water on the pump and cool it off then it will start fine again.Mine got worse and it finally wouldn't start at all. I put a new injection pump on it and never had a problem.Don

SliverPicker · January 18, 2014, 05:31:08 PM

Sorry, I quoted the wrong post!

SliverPicker · January 18, 2014, 05:32:58 PM

Quote from: duckslayingpro on January 18, 2014, 05:07:33 PM
Unless he has swapped it with a gas motor it will not have coils. If it is a gas engine that would be a good place to start.
does it turn over alot slower after it is warmed up? If so it is the hydralics locking the motor down. I know this sounds stupid but if it is turning over slower jerk the steering wheel left to right vigourly while cranking motor and it will start. It will be relieving the hydralic pressure.

Head in my hind end on this one. 8) Hilarious!! Sorry. :-[

cutter88 · January 18, 2014, 07:02:46 PM

Quote from: duckslayingpro on January 18, 2014, 05:07:33 PM
Unless he has swapped it with a gas motor it will not have coils. If it is a gas engine that would be a good place to start.
does it turn over alot slower after it is warmed up? If so it is the hydralics locking the motor down. I know this sounds stupid but if it is turning over slower jerk the steering wheel left to right vigourly while cranking motor and it will start. It will be relieving the hydralic pressure.

took the words right outa my mouth

SliverPicker · January 18, 2014, 07:35:50 PM

Nice! 8)

Northern Timber Harvesting · January 18, 2014, 08:35:15 PM

check the starter fluid

Northern Timber Harvesting · January 18, 2014, 08:37:57 PM

no seriously I second loggah's injection pump suggestion. I have had similar problems on 3 different machines, not long after the injection pump went bad the hard start after warm-up problem went away with new pump.