682 KT17 Series 2 won't start when hot

[harvester850]

I have a question for the experts on my 682 KT17 Series 2:

After I mow my yard and the tractor is hot, it will only sputter and then dies if I shut it off and try to restart it.

I have replaced the coil, plug wires, and condenser.

Pulled the plugs this last time and there was no spark when hot. Put is back together and it started right up.

Previous owner had a 2' long fuel hose and automotive in-line filter that I replaced. It looped up near the top of the tank - Vapor Lock? It started after I replaced this but it had cooled while I replaced hose.

It barely turns over and is running when cold or cools off a little.

Could it be the points or something else that I am missing.

All help is appreciated.

Denny

[MWShaw]

Originally Posted by harvester850

I have replaced the coil, plug wires, and condenser.

Have you replaced the points? Or checked the timimg?

Hard cranking when hot could be timing, or a weak starter.

Most in-line fuel filters a have a "direction of flow" make sure yours is not backwards.

[Matt G.]

Have you replaced the plugs, too? If there is no spark when hot, it's not a fuel problem unless you have multiple problems here. How are you checking for spark? The ignition system on the KTs and Magnums is pretty weak to begin with; I don't think the spark will jump a 1/4" gap, and I also don't recall ever having a nice, blue spark at the plug with any of these engines I've had, either.

[bkw3614]

After you have checked the other suggested issues, I wonder if your battery may be beginning to fail. Sometimes, the resistance can be higher in a hot battery; one that is being charged by the generator. Failure could be caused by either aging of the battery, or an improper adjustment of the voltage regulator.

I haven't had this problem with Cub Cadets, but found it to be a regular problem with the twelve volt system in my 1957 Chevrolet.

This is just a thought, as it sounds as if it starts fine when cold, but is dead when warm and working.

[harvester850]

Thanks guys.

To answer some of the questions:

The in line gas filter is going the right way and I agree that I don't think the fuel line had anything to do with it, but it was something that needed fixed while I waited. The old hose was really long and looped up over the carb and left cylinder. It was cracked and old and I thought maybe it was not able to pump up and over when hot.

I have not adjusted or changed the points and timing appears to be right on.

Not sure how old the plugs are. To test I just pulled them out and grounded them to the cylinder bolts. I may pull them and see if I get spark when it is cold.

Battery is fairly new and there are no cranking problems when hot. It turns right over hot or cold. I will check to see how much voltage it is getting when charging in case it is getting over charged & over heated. Had a motorcycle do that once.

It just sputters when hot but just won't stay running.

Thanks for all the suggestions.

Denny

[Matt G.]

Well it definitely isn't the battery then...if it is good enough to turn it over, it's good enough to run the ignition.

As long as the ammeter is working, you should be able to tell what is going on with the charging system. I highly doubt it is overcharging- I have never had that happen with the stator/rectifier charging system. I'm not even sure that's a possible failure mode.