SunStar with a Sputtering Kohler Magum 20 engine.

[dunoon2]

Customer has a Simplicity Sunstar with a horizontally opposed 20HP Kohler engine. I don't have much experience with this engine. After running about 35min+ it will start to occasionally sputter and even try to die, if I stop moving and turn off the deck, It will sputter back to life. I'm trying to figure out if it fuel or spark. I know that in years past Kohler had problems with the ignition. I noticed at idle it surges, so something might be up with the carb. Does anyone have any suggestions, they will be greatly appreciated.

Rich Davis
3-M's, Mobile Mower Maintenance Service.

[bgsengine]

I'd start with power balance test and spark plug inspection - may be running on one cylinder.. if power balance and plugs check out, then a leakdown test on cylinders to check for loose valve seats (Isn't uncommon on aluminum block/cylinder engines) which can seal fine when cold but come loose when hot...