I'm having a problem with one of my 01 Big Bears. When the throttle is near all the way up, the quad pops, putts, and tends to hesitate in going. I have changed plugs in it numerous times, only to have the quad do the same thing. I went riding last Sunday (Feb 2) and I just changed the plug the day before (Sat, Feb 1). The quad ran perfect that day. Full throttle, half throttle, wherever the throttle lever was, it ran fine. The other morning, since we had so much snow up here (Long Island, NY), I took the quad out and it ran like crap. It did everything that I mentioned above-popped, putted, hesitated. I brought it back to the house, and took the plug out. It was fouled. I put a new one in, and the quad still ran like crap. I rode it for about 5 minutes to see if it would go away, then brought it home and checked the plug. It was fouled. After all this, can anyone tell me what might be happening with the quad? A few friends told me that it was running rich and needs a carb adjustment - but the carb hasn't been adjusted since we bought it - November 2000. Anyone have any idea? The quad is still under Warranty. Should I have the Dealer check it out? The last time I went to the Dealer they charged me $37 bucks to charge a battery, which didn't last anyway. I'm a little reluctant to bring it back to them if I know all it needs is an adjustment. Thanks in advance to everyone.
-Chris H

 

get your carb flushed or at least checked out

 

I have a 2002 Yamaha BigBear and since i've had mine i've had problems with my fuses blowing. To adjust your carb. theres a flat head screw underneath i'm thinking its infront of the bowl. without taking the carb out when i had to adjust mine i used one of them flathead bits that you put in to them screwdrivers. But i just used the flathead bit cause theres no room for anything bigger. I'm also trying to think if you screw it in for less gas but only screw it like 1/4 turn each time until it seems to run normal. I did that cause i put a snorkel on my quad and i had to adjust the air flow mixture screw (what you need to adjust) Hope i helped some.

 

Is there snow in your airbox? You might want to check. More than likely thats your problem. Might want to try some isopropel as you may have ice in your carbs.