2001 Yamaha Raptor 660R Misfire

Mandy · January 25, 2010

Hi I have a raptor 660R it misfires and loses power when i go above second gear and i have it opened up full throtle does anyone know what can cause this?

**Ajmboy** · January 25, 2010

Hi I have a raptor 660R it misfires and loses power when i go above second gear and i have it opened up full throtle does anyone know what can cause this?

Welcome to QUADCRAZY! When was the last time you changed your plug(s)?

What year is your atv?

* Added Make to your thread title.

Mandy · January 26, 2010

Its a 2001 Model i think cant be newer than 2002

Mandy · January 26, 2010

I think they were checked like 8 months ago... Im having a hasstle finding a plug spanner that goes into my bike

**Ajmboy** · January 26, 2010

Its a 2001 Model i think cant be newer than 2002

Thanks...updated your thread title. Have you checked the plugs, air filter, and fuel flow?

**Ajmboy** · January 26, 2010

I think they were checked like 8 months ago... Im having a hasstle finding a plug spanner that goes into my bike

Can't you use a 3/8 ratchet, spark plug socket, and extension bar...with a swivel?

Mandy · January 26, 2010

I'll give that a shot thanks alot... my mechanic that used to fix my bike has left so wasnt too sure what tools worked... Um my bike didnt come with a manual are u able to tell me how to check the fuel flow? wen im ridding i make sure the tap is on all the time... ive changed the filters incl air and i had a new carb kit fitted but cudnt get the plug out to get another one.

IndyKWG · January 26, 2010

Mandy, your first post says if your above 2nd gear and have it "full Throttle" it misses out. Unless it has an after market CDI box it will have a rev limiter to keep it from over reving. If you shift to a higher gear but run half to 3/4 throttle how does it run?

Mandy · January 27, 2010

Hey Indykwg,

yea it does that in third and above i have the digital display on mine it gets to abt 3 on the rev counter then i change... i tired the throtle at about 3/4 and its like its starving for power or something then i open it fully and it still kind of jerks and like misses but if i drop all the way to first it somehow feels like it kick starts again and it rides fine.

IndyKWG · January 27, 2010

Definately change the spark plug. Its the cheapest and fastest fix. If that dosen't get it post back. Could be a bare spot on the coil wire shorting out or the wires to the coil shorting as the ride gets bumpier at higher speeds.

DirtDemon · February 9, 2010

Sounds like you are running out of fuel in the bowl, maybe an improperly adjusted float. Could be that the carb needs to be cleaned out as well. The other possibility I see is that the CDI or pickup coil could be malfunctioning. Couldn't hurt to check the valve clearance, compression and timing chain as well. At any rate, definately change the plug first, and look at the color of the insulator on the old plug, the condition of the spark plug can be a good indicator of your problem.

Mandy · February 9, 2010

Hey everybody

Thanks for all your help I have changed the plug and also changed the coils and floats and now its back to normal if not better thanks sooo much for all your help on this I feel like a super mechanic now