dont mean to put this on theblasterforum but everybody on here is so helpful and nice compared to other forums. so i have a crf 450r motor in a 400ex modified frame for a hybrid quad and i bought it non running. pretty much it has hotcams,full hinson clutch, je piston, and a tc racing straightpipe kinda exhaust. i had to replace the crank in it and i also did all the gaskets and seals in the motor. everything is in time the only problem i know it has is that the valves are loose becuase i guessed on the valve shim sizes.they are about double as loose as they should be. i think it has a 45 pilot jet and maybe a 178 main in the carb. i cant for the life of me get it to start from the kicker cold only starts cold by pulling it with a truck but it runs great when its hot and sometimes fires up from the kicker when hot. i took it riding last weekend and i thought i blew the motor because i was 4th gear wide open and it randomly died and refused to restart, i still dont know why but when i took the motor apart again everything looked fine. i cleaned everyhing up inside and honed the cylinder too. i didnt replace the rings on the piston though. if someone can help it will be greatly appreciated.