Quick question regarding Miller engine driven welders with the Onan engines in them (or any other small single or twin cylinder engine).

How often (how many hours) do you pull the heads on your Onans and decarb the engine?

Reason I ask is I've got an Onan that has about 400 hours on it. It is a twin cylinder aluminum engine, Performer P220 and is twin cylinder. The engine runs like a champ, but I've been advised to pull the heads and clean the carbon as a preventative measure. I've also read horror stories about folks doing this and twisting off tin and head bolts trying to get the heads off.

So my gut says, if it ain't broke, don't fix it. Somehow I need to address potential carbon build-up.

How often do you pull the heads on your Onans to clean the carbon or do you just run them forever?

On another note, is there anything you can do to minimize the carbon build-up in the first place? I've read some use MMO or Seafoam or spray a mist of water into the carb to burn out the carbon.

Any advice, tips, tricks would be much appreciated.