ive had my 02 raptor since new and i put on full yoshi exhaust, re jetted, and put a k&n filter. i also cut the air lid...people told me that was the problem. it ran fine for two solid years then just up and quit...i need help bad

 

what do you mean quit?
thats a broad area for things to go wrong.. people will need more info.

 

yeah, more info please. Did you do the rejetting and the pipe and airbox mods when it was brand new? So it's been modded for two years and you had no problems until a sudden death? .....

 

yes i did it brand new... one day it was running, the next it wouldnt start. i tried to pull it down the road with my warrior and it would fire for a second then quit, it would only stay running (still missfiring) at full throttle. now it wont even do that. i tried to start it with ether and it fired for a second then quit.

 

try cleaning the carb, putting a new plug in.. maybe check compression?

 

Mine did the same thing. It was the valve adjustment. My 02 just up and quit one day and I tried starting it and got the same backfiring and that was the last thing I checked after 3 days of trying to figure it out. Check your valve adjustment.

Let us know what you find out.

 

i dont have the knowledge of valve adjustment on motorcycle engines. any help with that would be great. also i took the carbs off and looked inside...looked clean to me., i have a plug cleaner/checker and it seemed fine.

 

just found a site that has this info...will try the valve adjustment first then get back with you.

 

If you want to check the valves and adjust them here's what you do:

Remove front fenders and gas tank. All rubber spacers and covers.
Above the head pipe on the front side of the cylinder are two 12 or 14mm bolts with what looks like big, flat washers/spacers attached to them. On top of the cylinder is the valve cover; remove all three of these things.

In your yamaha repair manual(which I hope you have) it gives you the right valve seat measurements. You can check these by inserting a feeler gauge. Use the adjusting nuts if the measurements are off. Your manual will also give you (better) instructions on how to perform this task.

If your carbs are clean and your plug too, I'm guessing it might be ignition. Check the lines to your battery and from the starter switch. In fact, check everything in the battery compartment. There could be a loose connection, if you're lucky.

One day my bike just wouldn't fire and wouldn't fire; it wanted to bump start but wouldn't get going. Turned out the postive wire came off the battery.

Also, if you had the carbs off, check to make sure all the boots sealed up tight. Good luck.

 

Try a new plug first. Thats how they usally act when the plug fouls.