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Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 13581
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
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I have a Honda GX670 on my stationary home generator that

Customer Question

I have a Honda GX670 on my stationary home generator that runs off propane. The engine starts fine, but after a minute or two starts to run poorly, occasional backfire, then quits. It will start fine, then again starts to run poorly and quit. I suspect the carburetor is plugged. I have read your post about Mechanic in a Bottle, but I have a propane fired engine, not gasoline.
Submitted: 1 year ago.
Category: Small Engine
Expert:  Vince O. replied 1 year ago.

Hello, have you ever checked the valve settings?

Customer: replied 1 year ago.
No. The engine has 125 hours. Once some of the snow melts here, I will check the spark arrester, which is recommend maintenance.
Expert:  Vince O. replied 1 year ago.

A backfire could be a valve problem. I had a portable generator doing the same thing (13 hp Honda engine). The valve lash was off. Adjusted and it ran ok.