Ok this bike has fought me ever since i bougt it. Ok so far I have redone the carb put new intake valves in(originals were cut and sucked up into the head. After these two fixes the bike ran great. Over the wkend i took it to a local race. During the time i came off a jump and then went into a turn and the engine(i think) let out one loud tink. After that it lost power. You can ride it for about 10 secs then it shuts down. The engine now has developed tinks that come from the engine.(I think) I have no clue what is wrong unless it is just over heating. If anyone has any ideas can you please help.