I own a 2008 Hisun 500. When i bought the machine the cam and cam gear were broke and it was partially disassembled.I order and installed the new cam and gear. I timed the gears and installed the timing chain. I closed a few things up and starter the engine it ran for 10 minutes then stopped. The timing chain fell off. I am not sure if the timing chain guide on the exhaust side (yellowish colored) is in the right place . Is the top of the guide suppose to set under the groove in the cylinder head or on top of it? The top of the cylinder head is one piece unlike the one pictured in the manual I own. Your help is appreciated.