My numbers are working backwards from A) the rating of the genset and B) what I know the engine turns out to be. I noticed the exact same engine turning up on Lugger, Northern Lights and two other brands of genset (After turning wrenches for a while you learn to recognize things in the dark). A guy at a boat show identified it as a Kubota 18hp, so in my application it's loafing.

I still say the math doesn't work. 18hp cannot sustain 60hp output. And that torque figure is at full stall, not pulling a 31' Airstream up a mountain pass. Ain't happening.