Have a 10hp tech. mod.lh358sa on a snowblower rebuilt carb. checked for air leakes none no abjustment on carb. govenor working properly engine still surges up and down as if it is sucking air. any help would be appreciated. Thanks

sound like a blockage still in the carb i have had very good resolts with a ultrasonic cleaning tank on 2 stroke carbs like this one hope this will help

does it still surge when the auger is engaged?

does it still surge when the auger is engaged?

Good point - many engines today (and for the last 15 years)are jetted to run smooth ONLY under load.

While it is running and surging spray carb or brake parts cleaner along the mating surfaces behind the carb and intake, if the engine tempo changes you have found your leak if there is one. Have a good one. Geo

took apart cleaned again just in case put all new gaskets still doing it even with the auger engaged I figured maybe because of the warm temp. so I went out this morning when it was only 16 out and it still does it sprayed carb. cleaner around all mating surfaces and no change.

Does it spit any gasoline out the carb when surging?

no gas spitting out but I sprayed carb. cleaner around throttle rod and it stopped doing it. took apart and it dosnt look worn no gasket on top now what?

Sounds like the throttle shaft is worn out and possibly the carburetor body itself, you can try a new throttle shaft but it that doesn't work your looking at a new carburetor.