I just picked up a blaster that has a full fmf, foam filter, no lid, and bored 30 over. The bike didn't run when I got it opened it up and there's a hole in the center of the piston. Plug was correct and main jet is 330. Any ideas? First I'm thinking main jet is too big and the gas was very blue when I emptied tank not sure if they ran it straight gas then added oil when it blew up or vise versa
Bike melting piston
- Thread starter Joseph296
- Start date
Air leak.
A rich mixture should not burn a hole, lean mixes due to an air leak or detonation causes by low octane fuel will destroy the piston.
Too much oil in the mix will too lean out the AFR and cause the same thing.
A rich mixture should not burn a hole, lean mixes due to an air leak or detonation causes by low octane fuel will destroy the piston.
Too much oil in the mix will too lean out the AFR and cause the same thing.
air leak #2
jetting sounds rich for those mods, thats not a engine killer.
air leaks and detonation from too low octane fuel are.
compression determines octane required, doubtful that was a cause without a modified head.
leakdown test the new engine
possibly too much oil mixed in with the fuel ? that actually creates a lean condition also.
air/fuel ratio lean, same as jetted lean or an airleak
jetting sounds rich for those mods, thats not a engine killer.
air leaks and detonation from too low octane fuel are.
compression determines octane required, doubtful that was a cause without a modified head.
leakdown test the new engine
possibly too much oil mixed in with the fuel ? that actually creates a lean condition also.
air/fuel ratio lean, same as jetted lean or an airleak
Nope pretty sure it said 330 lol is there suppose to be 2 gaskets on the reed cage one between cage and motor and one between cage and carb? I took it apart there was one on motor side and just some silicone residue not enough to seal anything on the carb side
There is supposed to be a gasket between the reed cage and cylinder, but no gasket between the cage and carby boot.
The boot has a rubber sealing device but if the bolts have been tightened down to more than 5.8 ft lbs the boot will warp, and will leak.
High temp copper RTV can be used to correct the warpage, but the bolts must not exceed the torque recommendation and should be tightened diagonally and incrementally (a little at a time).
The boot has a rubber sealing device but if the bolts have been tightened down to more than 5.8 ft lbs the boot will warp, and will leak.
High temp copper RTV can be used to correct the warpage, but the bolts must not exceed the torque recommendation and should be tightened diagonally and incrementally (a little at a time).
