2001 Yamaha Raptor 660 Idle Problems

[raptor_rider]

i have a 2001 raptor 660 and whenever im riding it and i let off of the gas it will sputter. it also does it after im riding it a while and i let it idle it will sputter every once in a while. any ideas wheat the problem may be.

[outlander560]

does it sound like it is about to stall

[Sparrows]

no no no, check your jets. what modifications do you have? might want to rejet properly

altho i found your problem "raptor"

dooh ho ho ho!

[raptor_rider]

there isnt any modifications really. only thing i can think of is when i had it worked on bout 6 months ago the mechanic put a 1.5 inch hole in the top of my filter box.

[Stoopidbot1]

My first thought would be to rejet.

[Sparrows]

it's in your carb then. i would rejet, your quad is sucking more air. might not sound like a lot but anything affects it really. dont you have a air/fuel mix screw? yeah tinker with that a bit too!

[outlander560]

i dont think he has to rejet if he didnt do any mods their would be no need...it could be as simple as u needing to clean out ur carb..

[Sparrows]

hurrhurr sure.

[outlander560]

alright y would he have to rejet if he didnt do any mods?? it doesnt happen out of no were.. the only way i could think if he went higher in elevation

[raptor_rider]

no change in elevation

[raptor_rider]

how would i re jet if thats what it needs. i already cleaned the carbs

[outlander560]

if u order a dyno jet kit it will give u all the directions u need to install it.. or any jet kit will give u directions i think

[raptor_rider]

alright, how much does it usually cost, is it easy to do

[Ajmboy]

Sounds like you just don't have enough fuel in the carb bowl at low idle. You said you cleaned the carb, did you take it apart and look at the float pins and check for free flow movement?

[raptor_rider]

ya took the whole thing apart. its usually right when i let off the throttle and its like it skips a beat

[DirtDemon]

alright y would he have to rejet if he didnt do any mods?? it doesnt happen out of no were.. the only way i could think if he went higher in elevation

He said that there was a hole added to the airbox lid, that would be a good reason to jet a little richer.

[outlander560]

yea i was thinking that but that was 6 months ago and now the problem started so thats why i didnt really pay attention to it

[DirtDemon]

Good point.

[mywifeknowseverythin]

I would start with the The jet needle.... its most effective between 1/4 through 3/4 throttle and wont cost you a dime if works....Also The air screw is most effective between idle through 1/8 throttle......that also will not cost you anything....Dont do them both at the same time though....Make a Change and Test it....If that doesnt work...Move to the Second Operation and Test.....Also,,,,Whenever I drill Holes,,,,I Sneak a pair of the Wifes Panty Hose thingies and Cover my lid.....Kinda like a Pre Filter....

Oh BTW......Make DAMN SURE you are Checking your PLUG!!!!!!!

.

[raptor_rider]

so i covered up the whole on the air box just to see if it would make a difference and i rode it for bout an hour and it seemed to fix the problem. it still idles a little rough and every once in a while when its idling it will die unless i turn up the idle a little bit. i dont know if thats just becasue its an 01 and its got some miles on it. what do you guys think

[hedgehog150]

Sounds to me like it is lean. You can jump up 1 size pilot jet. I would recomend the Dynojet kit, it is the easiest and fastest, they have done all the testing. You can also make changes later with the same kit if you add any more performance parts. Jetting the Raptor is a huge pain in the rear without the Dynojet kit

[mywifeknowseverythin]

Sounds to me like it is lean. You can jump up 1 size pilot jet.

I am going to have to Disagree with you there..

If your main is too rich, the bike will sputter and surge as it tries to burn all of that fuel.... Too lean,,,, and the bike will run flat or have a flat spot in the powerband... A severely lean main will cause your bike to seize just like a two-stroke.. It's better to be slightly rich on the main than slightly lean, because it will run cooler.

Your pilot jet (or slow jet) controls the idle circuit, or from zero to one-quarter throttle opening. The pilot jet and airscrew control the amount of fuel and air going into the engine at slow engine speeds. It's very important to tune these circuits because they control throttle response and starting.

When you are Tuning, Make sure you are at operating Temp.

One Question that has never been Asked..Do you know what the Stock Jetting is and What you are running now????

Another thing.....There Really is NO POSSIBLE way to Jet a Carb over the Computer...You either know what you are doing or you dont...Plug Chops are KEY IMO when Jetting...You dont know if you have done it right until you read the plug....

Do us all a Favor......Install a new Plug......Do a Plug Chop.....Immediately take that out and snap a Shot.....(to post here or reference for yourself....) That will give you a starting point....Each time you Jet.....You need to install a new plug.....Keep reading them until its Right....

Everyone has given Good advice....I just think at this point we need to stop and Start all over again.....

[raptor_rider]

i bought it about a year ago and i have no idea if its the stock jetting or not. i did take out the plug and noticed that it was really dry.

[Ajmboy]

i bought it about a year ago and i have no idea if its the stock jetting or not. i did take out the plug and noticed that it was really dry.

You're running too lean. Your air/fuel ratio is off. I would plug that hole, clean or install a new filter, and install a new plug.

[DirtDemon]

i bought it about a year ago and i have no idea if its the stock jetting or not. i did take out the plug and noticed that it was really dry.

The idle problem may be remedied by adjusting the air screw. Did you notice the dry plug before or after you plugged the hole it the air box? What color is the plug?

[raptor_rider]

i noticed the dry plug after i plugged the hole in the air box. its was kinda a lightish gray color

[raptor_rider]

Your pilot jet (or slow jet) controls the idle circuit, or from zero to one-quarter throttle opening. The pilot jet and airscrew control the amount of fuel and air going into the engine at slow engine speeds. It's very important to tune these circuits because they control throttle response and starting.

it sounds like i need to adjust my airscrew becasue i chokes at slow engine speeds ill try that this weekend. how do i go about doing that

Edited April 14, 2009 by raptor_rider

[DirtDemon]

It is a screw on the side of the carb, should have a spring on it, you probably can't see the spring unless you completely unscrew the screw, but you can feel it when you turn the screw. It will be low on the carb, but not in the side of the float bowl. Turn the screw in to richen, out to lean it out. Adjust the screw so that it idles smooth and the throttle response is good, no stuttering. However, you also probably need to either make sure the hole in the air box is sealed or, go bigger on your main jet. Follow MWKE's advise and get a coulple of plugs and do some plug chops. Make an adjustment, install new plug start the bike, warm it up and ride, get the bike wide open in as high a gear as possible then pull in the clutch and hit the kill switch. Pull the bike over, take that plug out, put your old one back in, and ride back. Take the plug you removed and chop the side of the threads off so you can see the lower part of the insulator. You want to see a medium to dark brown color. Light gray means you are running too lean. You either need more fuel or less air. After you get the main jet set, then if needed tune the needle and pilot if you think you need to. Also, you may want to search for some jetting tips on your browsers search engine, google works best IMO. Reading a good article on jetting will help you understand what you are trying to accomplish.

Edited April 16, 2009 by DirtDemon

[raptor_rider]

so im having trouble finding the air screw, is it located on the outside of the carb so i can just adjust it without taking the carb apart. and is there two of them, one for each carb

[mywifeknowseverythin]

do you have the ability to take a good picture of the Carb and post it???? We could then Circle it and show you......My next Action would be to drive down to the Yamaha Shop and Buy a Manual before they close....

No offence to you....I know(just like me) some people dont learn unless they do....But this is a Pivotal part of the machine....If the carb isnt set right...Your next post will have the heading...."My Engine is Locked up, What do I do?":huh: