Heymow - Lawnmower Racing Forum

Engine Help => Briggs OHV & Vanguard => Topic started by: slideways on August 18, 2020, 08:23:45 pm

Title: Grass Cutter Model 31 sounds choked down
Post by: slideways on August 18, 2020, 08:23:45 pm

I have a really low hours 18.5hp Model 31 on a mower that had some random smoke issue that i was told was probably a head gasket. I replaced it and put a chinese carb on since the solenoid leaked. Beforehand the motor ran fine and sounded strong and it also ran ok right after the head gasket install once i got the carb tuned ok. The issue i have now is that under a load (like any time the PTO) is on you can audibly hear it "snorkling" through the intake and its noticeably short of 3600rpm. I tried with/without air cleaner, rechecked the valves, torqed the head, even removed the muffler since it was like there was a restriction and it will run full throttle unloaded but just lacks the loaded rpm. It idles ok so i dont suspect a head/vacuum leak. It will actually idle so smooth that it will chug at like 400rpm like a hit and miss engine if i get it that low.

Title: Re: Grass Cutter Model 31 sounds choked down
Post by: birdman_express on August 25, 2020, 08:11:15 pm

Sometimes them $5 Chinese carbs are not worth it.