yeah that might be needed. The Cat seemed to have adequate power with the tires. I'm at altitude (6000 feet) so I'm losing a fare bit of power due to the thinner air but I was always reasonable happy with the power.
The shop did something to the engine that isn't good. It isn't making nearly the power it was before. The engine is very slow in throttle response and coming up in RPMs and sluggish to come down in RPMs. The governed RPM seems way lower than factory.
I found a Kohler authorized service center in Bozeman. Phoned them and they said they know nothing of these engines.