I have a 2004 yamaha raptor 660 i got it cheap because it wouldn't turn over. well i roll started it and it rain like a beast. but i hard the timing chain slapping. so i broke it down put in new decompression mech. new chain, new radiator , new starter , new starter clutch , new starter relay, and adjusted the valves they where super tight, got it back together it ran and startered up great. well i went out to start it and the thing did what it did when i first got it . the starter seems like it doesnt have enough power to turn the motor over and then the relay just clicks and get super hot. it will turn over til it hits compression stroke. not sure if the valves tightened back up or the starter is weak. i went ahead and replaced the relay again as well but still same issue.

 

Far more likely to be a flat battery or bad battery connections than anything else. Tight valve clearances drop compression so it isn't that, could be you haven't got that decompressor right, but there isn't a lot you can get wrong with most of them.

 

Well, actually the exhaust valves were loose causing the decompression mech. to not work. so I tightened the valves up and she fired right up. Thank you for your input!

 

Bet you set the valves on the exhaust stroke first time round, no wonder they seemed tight. They must have made quite a noise when they were set so slack the decompressor didn't work.