My raptor has recently started to overheat. Here are the things I have done in the past 3 months: Replaced water pump, and added new coolant/antifreeze. General service: changed engine oil, replaced sparkplug, and adjusted the valves. I pulled the spark plug this morning, and center electrode, is just an off white. I am thinking maybe after I serviced the valves, that it made the machine run a little lean, but would this through the engine off into overheating? I called the Yamaha dealer, and asked about the thermostats, he wants $20, but he said "put it this way, we have never sold a thermostate for any year Raptor." I checked the fan this morning, and it turns fine when connected to a 12v source. But will not come on when the engine lamp comes on. I do have the factory service manual, so I am checking different systems.

 

The dealer also said I might have an air bubble in the lines, and that I need to bleed it. I thought this was only for brakes??

 

Well I got to taking things apart since my last post, and I found out that when I put the spark plug back in, i didnt tighten it all the way. I still had about a 1/4-1/2" left before it was seated against the head. There was alot of dust/dirt in there so I cleaned it out, got the spark plug seated correctly, ran it hard for about 10-15 minutes, and it's not overheating yet. Could this have caused it to overheat? The bike runs 10 times better now [img]i/expressions/face-icon-small-smile.gif[/img]. Still open to any comments/advice. Thanks
John

 

hey jus wanted to BUMP your thread i have the same problem, hopefully someone will reply

 

Check the fan switch if the fan is not coming on.