What is this?

[barmcd]

This picture is in an ad for a 1999 Monaco Diplomat on RV Trader. I've never seen anything like this before.

[wolfe10]

And spark plug replacement or valve adjustment would likely require removing it from the coach.

[Pogoil]

Onan 5500 or 6500 generator. Very easy to change brushes mounted that way.

Pogoil.

[dougrainer]

Onan Genset. Mounted sideways due to mounting in the front of the Motorhome. The pass side would be the actual "front" of the Genset. Doug

[barmcd]

Okay, Most of the generators I've seen in motor homes are in a metal box so you don't see much of the mechanical parts.

[wolfe10]

Air filter is black box on the left with the two on-generator breakers below it.

[gbopp]

wolfe10 wrote:
Electrical end of generator.

Yep, and it appears to have an hour meter at the top right.

[wolfe10]

Electrical end of generator.