[SilvercliffBluestreak]

Someone came to me with a question on a Yama Mountain Max 77 triple. Two of the three holes run reaaly lean. The obvious has been checked, air leaks, carbs swapped with known good, case and cylinders pressure tested. All things point to the labyrinth or base seal. Anyone seen anything like this?

Thanks!

 

[madcow]

the labyrinth seal is a seal made by the oil and gas mixture around the crankshaft. its not a mechanical seal like a rubber crank seal.

how are them 2 cylinders jetted compared to what its suppose to have?

are the carb boots in good shape? vent lines in good shape. air box mods, or it could be a simple crank seal that is bad. spraying stuff around a crank seal wont make an engine rev up, but you will smell the exhaust change.