G2 new issue

[sillyrabbit72]

Hello everyone!

I have a Yamaha G2 that I have been working on and driving around for about a year now. When I bought it I rebuilt the engine as it was smoking terribly but since then it has been great. This past weekend I was driving it around and all of a sudden it started slowing down and smoke started coming out of the valve cover breather tube so I pulled over. I'm running a fresh K&N air filter and have tried everything I can think of. When I put the cart in neutral it revs up fine and the clutches shift well, but when I'm driving the cart it doesn't seem to want to rev up like it used to.

I also noticed a knocking when I let off the gas if that clues you into anything.

List of things checked:
replaced oil
set valve lash
checked fuel pump
visual inspection of clutches (everything looked alright but I'm no pro)

Thanks for any help y'all can offer as I'm stumped currently.

[mustangwagz]

Do a compression test on it... doesn't sound good to me.. when mine cooked the oil rings, thats what it did exactly..

[sillyrabbit72]

I'll check it out thank you!