I was out on my raptor yesterday in the snow. In eastern PA here we got quite a bit. Anyway everything was going fine and I came home and went back out in say an hour and first it wouldn't start and the reason being the throttle cable was stuck. After that was taken care of and this is the wierd part, I'd start it and it would sound like it was on choke even if the choke was all the way off and if you just tap the throttle it revvs extremely high for 5 seconds even if you let go and then it idles really high. I tried adjusting the idle screw and no matter how high or low i turned it there was no difference. And i checked the throttle casing and all the workings in there are fine. I love my raptor and everything up to this point was fine and I want to get back out riding and it runs but I think it is unhealthy. The head pipes get red hot I mean they are bright, I never noticed this before either. So my questions are this, 1. how many turns out roughly should the idle screw be? 2. Has this happened to anyone before? 3. How can i fix this? Thanks

 

Cold air is very dense. Meaning your bike is getting a lot of it. If the pipes are glowing red that means your bike is running extremely lean. Your gonna need to jet it up about two stages. Watch the plug. Ideally you want the porcelain to be a light tan color. Yours right now will be white. An extremely lean air/fuel ratio can melt pistons. You need to fix it soon.

 

happened to me the other day....it was also very cold and i turned the choke on to start it and then i pulled the choke off or back to normal position and i could tell the choke was still on because of high and rough idle...same stuff as yours...i just worked the cable back and forth and it finally let loose..your choke is just stuck open

 

Glowing exhaust is usually due to the combustion process continuing into the exhaust stroke.

This is most probably due to two things:
1)Too rich of mixture.
2)Too late of spark advance.

Since nothing was done to the spark advance it is most likely caused by a rich mixture.

The choke being stuck would cause a rich mixture.
So check the choke first before doing anything else.

 

Call me crazy but check your carb, you might have lost a screw.

 

i did notice my air filter was slightly out of place too. is it possible that some snow got in the carbs and froze?

 

Doubtful, if anything you got sand in there but probally not, if the filter is off it will rev high cuz its getting more air, might be the culprit...

 

Ha Ha...some of the responses people give are amazing! Make sure and get the air filter in correct and make sure it is in perfect while taking your time (the top of the filter is actually labeled TOP). My idle circuits are set as follows: LEFT-3 turns out RIGHT-1.5 turns out (this side operates 2 valves). Going one size up on the pilot jets is will help ritchen up the idle circuit as well in this cold weather. Stock is 22.5 and 25's should work. Pilot jets are very hard to find for the Raptor right now. Go to WWW.sudco.com, and give those guys a call...they should be back in this week.

 

The same thing happened to me yesterday. It was about 20 degrees out. After riding awhile i went home and left the raptor outside. I went back out about an hour later and warmed it up with choke at half closed position. After a few minutes I opened the choke. I noticed right away there was no change in sound/ or idle speed. After warming up for a few more minutes the choke opened up, and everything returned to normal. I normally park the raptor inside. yesterday was the first time i left it out, and the first time this has happened.

 

My choke was stuck and when I was working it loose I think I stretched the cable if it's possible. I put a Sparks ign. Advance key in and the Big Gun slip-on and it's running real rich, fouling plugs(I'm not puttin' around either). If I put the headers on will this alleviate the problem some. I think I have to rejet but at my elevation 1200-1700 with the advance key shouldn't it be close with the full exhaust?