kohler 20 hp using oil

[little harold]

i have a kohler 20 hp v twin that has started using oil about 1/2 to 1 cup per usage and plug is fouling. how would you go about pin pointing the problem.:confused2:

 

[Rivets]

I suspect blown head gasket. While it is running at half throttle slowly unscrew the dipstick and see if it rests on top of the tube. If you feel a lot of pressure and the dipstick jumps all over, I would be replacing the gasket or gaskets if both plugs are fouling.