The timing had jumped on my 660 and sputtered and stopped. I pulled it apart and found the timing chain was loooose. Before this happened it was blowing the blues. So I pulled it apart bored it out, put a new piston and rings in, it didnt really need it but i replaced it anyway. I figured while it was apart i would put a hotcam stage 1 in and new timing chain. When I put it all together it would just backfire or pop. WHAT IS THE PROBLEM??? When I timed it I lined the sprocket with the 3 marks one on each side and the top one facing up, timing was TDC, then the cam went in with the lobes facing down. I was told the lobes could go up but there would be tension putting the head down??? is this a correct statement???. I did a leak test on it and the intake valves leaked, could this be the problem why it is not starting ??? Oh spark is fine at the plug not an ignition problem and the decompression pin in the cam is working fine. Any help with cam alignment and opinion on the valves will be much appreciated thanks in advance..

 

You say you lined up the 3 dots on the cam gear, two even with the top of the head and the center one at 12 O clock from those dots. There is also a dot on the decompression lever. It also needs to be at 12 O clock other wise the decompression pin will be keeping the exhuast valve open all the time. The oiling holes on the cam need to be at 12 O clock also with the decompression pin sticking out of it's hole around the 10 O clock area when installing the gear and aligning the marks. Once together put everything at TDC, align the marks on the flywheel etc and adjust the valves to their proper clearance. If all this is good, check the carbs to be properly seated in their boots all the way in and tightened.