My buddy has an 02 raptor 660r. It has been very problematic. It first sheared all the starter one way clutch bolts and broke the timing chain. I go the pleasure of fixing both. I did a leak down test on the motor and it produced only 2% leakage, awesome. However the cranking compression seemed low, I don't remember the number. Also I double checked the cam timing, it is right. I don't know what normal cranking compression is, anyone know. This quad has a white brothers slip on, a K&N and an edelbrock carb. Well here are the problems it has with starts and idle. It takes forever for it to start, the quickest way to get it to start is by pouring some gas down the throat of the carb then holding the throttle all the way down, it was like this with the stock carbs and the new edelbrock. This is in 40 degree Cali weather. Once it warms up, it either idles too low or too high, can't get it right. Also some times it will just have a quick single missfire at idle every minute or so and then the idle comes down. I am thinking besides the carb needing a little enrichening, It has an electircal/ignition problem and or the cam decompression thingy is not working right (it did move freely when I changed the broken chain). Any input or experiences would be great from everyone. My buddy is getting sick of his quad. Oh yeah, it runs great once warm and while riding. Great power too.

Thanks in advance

 

Sounds like some kind of vacuum leak to me. Make sure the carb is good and tight.

 

check to make sure each carb is getting fuel. turn the drail screew on both and see if fuel drains out.

 

Has a singel edelbrock carb and no vacuum leaks, all new stuff, just double checked with carb cleaner to make sure also. Anyone else?