engine wants to diesel

[tinnerjohn]

Cub Cadet 122 with a K301 engine, Runs great but it has started to diesel when the ignition is turned off. usually only after its been run for about an hour or so while mowing. Any ideas will be appreciated.

John

 

[Eugene]

Couple of thoughts, both heat related.
1. Debris in the cooling fins. Blow out with compressed air.
2. Carbon buildup in combustion chamber. You can try a fuel-based solvent or remove the head and clean.

 

[tst]

idles to fast, timing

 

[tinnerjohn]

Thanks. I was wondering about timing, it starts hard like an engine with the timing slightly off, but my experience with one lungers is limited. I've been using a small amount of Sea Foam most of the time in my mowers. Will take a blow gun to it also.

 

[Eugene]

Ignition timing is fairly easy. Just a PIA to get to the points. You can find instructions on YouTube or download a manual.

I have ball valves for fuel shut off on my Cub Cadets and farm tractors. I turn off the fuel, let engine run until it dies from no fuel, turn off ignition.