Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

have vtwin that i just cleaned up the carb on........it starts fine but seems to be blowing air/exhaust etc  out through the carb........not the breather tube but through the choke plate opening...runs up to speed but something is rotten in Denmark......
stuck valves,,,ring blowby.,,,,head gasket

Just had a similar problem with a 11hp briggs L head on a pressure washer that I bought for cheap.  I went through all the normal stuff Plug, coil, timing, bent/sheared key, stuck valves, valve lash etc. 

It would appear  that the person that had it before me had someone replace the carb.  They installed the wrong carb gasket and it was uncovering an air bleed hole in the face of the carb that should have been covered by the gasket.


The engine would surge at high rpm and spit / push air out of the carb past the throttle and choke plates and would run very rich at idle then stall.  It was a fixed jet carb with no idle adjustment.


After many hours of troubleshooting then discovering the gasket problem and fixing the gasket the engine now runs like new.

the entire problem with the engine was that someone had put the wrong gasket between the carb and the intake manifold.

Good luck

Carl

make sure the valves are adjusted properly...