Problem with surging at lower RPM

[Chris Parman]

I bought a used HR215 (from original owner who bought it on 5/20/1994). Got it home and changed the oil, cleaned the Carburetor (just sprayed it with carburetor cleaner, didn't take it apart) and put the carburetor back on. The issue is the engine will only smooth out when it is in full choke (meaning throttle lever all the way forward), if I pull the throttle lever back a little the engine surges. By the way, the GXV140 engine doesn't smoke (no blue or black or white smoke out of the exhaust). The spark plug was dark (probably carbon build up) but is now starting to lighten up. Any ideas on whats the cause is with the surging issue?

 

[ILENGINE]

you have a partially clogged fuel jet in the carb. Will need to remove and disassemble the carb and give it a good cleaning.

 

[HurstGN]

Or one of the gaskets was previously installed improperly. There is a small passage that goes through the gaskets and if the gaskets are not in the correct orientation, the engine will surge.

 

[tadawson]

I had an HR215 that I have owned since new that did the same thing. Theissue ended up being that the pilot jet (plastic) had apparently shrunken over the years, and no amount of cleaning would addtess the problem - always back in weeks. I did nothing more than replace the jet, and it has been perfect again for over 5 years . . . . These are tuned so darn lean that it doesn't take much . . .