Hello, I'm helping a friend out with a 02' Bear tracker 250, It doesn't idle well until its FULLY warmed up and it also has a glowing red header if ridden hard so I figured id adjust the valves just in case- but Yamaha does not publish the specs in the Manuel. Does anyone on here know the valve clearance? Is the glowing red head pipe normal, it looks like the same thin wall pipe my friends raptor uses?
Thanks, Joe

 

if its glowing the pipe chances are the timing is out . take out the big allen nut on the reverse lever and take the cap off the head on the left side of the head and bring piston up to top and check timing marks , being a 250 it probably has a worn camchain or tensioner and has slipped .

 

that could be, it will idle ok then all of the sudden misfire and die out of nowhere, ill check into that. Joe

 

was it the timing that was making the bike idle bad. i have the same bike and it does the same thing. i don't know if i need to adjust the valves or the timing

 

sounds like a lean running issue

 

my yamaha bear tracker wont gas fully. it pops and sputters and i cant fully throttle it wothout it doing it.. any help?

 

The not being able to go full throttle is either broken intake boot between carb and head, lack of resticted airflow (the beartracker has a restriction style air supply to the carburetor. If you snorkel it for creekriding it alowes it to breath more than it was supposed to from factory. Solution to that is a 1inch 90 pvc fitting on the end of the snorker and the factory snokel cut the end off where it slips into the slot made on the gas tank and place it inside the airbox over your pipe going into the airbox. On the piece you place inside the air box you will notice that the hole at the end of the piece is smaller than the size of the piping. Aka restriction) the stator could be weak cutting down on firing the plug, last but not least the cdi box. I would start with the simple fixs then work up to the more pricy fixes. hope I helped someone I know that I wished I would have found this out sooner because I spent years trying to figure out what was going on