trouble with vertical shaft 15 HP Kohler

[brdmkr]

A friend of mine has a 15 HP Kohler mower that runs and then stops when it gets hot.  When he lets is sit and it cools, it cranks back.  Sometimes it runs longer than others before going dead (sometimes 10 minutes or so, sometimes an hour).  Any ideas?  This is kind of similar to the way my mill acted when I had trash in the bowl, but my mill would never run more than just a few minutes.

[Radar67]

Could it be low on oil? Plenty of oil when it is cool, but as it runs it slings oil around inside and reduces the level enough to activate the low oil sensor. Just a thought. :P

[brdmkr]

Don't know Stew, but we'll check!

[isawlogs]

 I would look at the coil .. and or the capasitor . They will do what you are descibing work till hot , then quit till cooled down .

   Once it quits , check for spark , you might find  no spark or very weak spark . 

[sawguy21]

He should remove the fan cover and make sure the cooling fins are clear.

[bck]

I would look at the coil .. and or the capasitor . They will do what you are descibing work till hot , then quit till cooled down .

   Once it quits , check for spark , you might find  no spark or very weak spark . 

+1     Yep, this would be my guess too.

[mike_van]

Sometimes the gas tank vent will get stopped up too, it'll draw until it creates a vacumn, then the engine dies. The cooling off time is enough to let the tank get back to normal. You can try running it with the cap cracked loose to see if it helps.

[brdmkr]

Well, he has called in a pro.  It does get spark after it dies.  It also has plenty of oil.  We did not try the gas cap, but I will tell him about it.  I'll also post what it was when it is finally fixed.

[John Bartley]

There's a couple of model types of 15hp Kohler motors. The old CV15 Command motors are pretty good and trouble free for the most part these days. There's a new model (I forget the "name") which uses an inverted type of motor arrangement where the oil pan as we would normally think of it is on the top and the crankcase is upside down forming an oil "bucket". There are good little motors and very easy to work on. The troubles I've seen on there are sheared flywheel keys, broken decompressor mechanisms and broken wires to the fuel solenoid on the carburetor. These were all warranty troubles on new units.

cheers

John