I am a certified service tech on these unit and hands down without a doubt in my mind I would choose Kohler over Generac. The older series 1 generacs were great units. Last 7-8 years they have went downhill faster than an Olympic skier. Very few calls on Kohler. Sitting here waiting for this storm to hit and I know once it does i will get at least 4 calls on Generacs not starting.
What about the Cummin/Onans?
Do you also service the Kubota diesel generators?
