Carb issues

I have a 06 660 it has a k&n air filter , lid on , i did block the cab vent off to cut out noise , it had a hmf pipe on it when i bought it but i removed the muffler and put stock muffler back on . I think the header pipe is actually aftermarket not stock . So here is my issue , it takes forever for it to warm up and it stumbles at idle sometimes. Im pretty sure its all stock settings in carb . I didnt know if i should adjust the air fuel screw or what. Any help would be appreciated. Oh i do have JBS sheave & msd speed enhancer but i dont think that would affect carb.

I'm no wrench head, knuckle bustin mechanic, but my thoughts would be, if it had an after market exhaust it could have had the carb re-jetted; any time you restrict the air flow to the carb it will have an effect on the carb's proformance. Have you tried adjusting the carb or idle screw? I know how to shoe a horse....

no i havent tried anything yet ! I wanted to but thought i would ask and get some pointers first then do it .

pull the spark plug and check it. it will tell you everything you need to know about your air/fuel mixture.

http://www.ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp

make sure you have fresh fuel. if you don't know, then dump it and start with good fresh premium.

manual says idle speed is between 1450-1550 rpm. it will sound fast to you. try raising the idle speed if you think it sounds slow. you can always lower it or raise it more later on...

post up later after you try all of the above and someone on here will be able to help you.

I agree with these guys. Should have been re-jetted for exhaust and when You took it off it would probably run rich causing the issues. Like Steve said, pull the plug and check for color. It might be worth buying a new plug, run it for a while then pull and check. May be as simple as A/F adjustment

Sorry Denny ! was thinking about Steve.

oops i think I just deleted a thread.

If it hasn't been touched and the carb is still factory I would go up to a 150 main jet and leave the polite jet at a 40 and on the bottom of the carb is a brass plug that has to be drilled out and the air screw is under there. Once you have done that close the screw all of the way off and then open it back up 2 1/8 turns that should help you out.

southark wrote:

If it hasn't been touched and the carb is still factory I would go up to a 150 main jet and leave the polite jet at a 40 and on the bottom of the carb is a brass plug that has to be drilled out and the air screw is under there. Once you have done that close the screw all of the way off and then open it back up 2 1/8 turns that should help you out.

Polite jet. What about the rude jet? Anyways, the KN filter combined with the exhaust probably means it time to rejet. They tend to be lean from the factory anyways. I would even look at going up a size on your pilot jet and then adjust your a/f screw. I think James may have an A/F gauge you can borrow if you really want to tune her in.

Spell check is a bitch LOL and your right he may what to go up to a 45 or 50 on the pilot.

I asked the previous owner if he did anything to carb , he said he didnt . I was thinking the header pipe could make a difference even though i have stock muffler on it . It runs fine if i let it warm up for 10 mins or so . I will check plug 1st ! Thanks for all the info .

southark wrote:

Spell check is a bitch LOL and your right he may what to go up to a 45 or 50 on the pilot.

I know what you mean on that spell checker. I've thought about turning it off more than once.

Yes sir ! Lol

what used the a/f mixture be at idle and at WOT. i have a gauge and trying to dial mine in. at idle i am at 13.3 and WOT am at 10.5. anh help?

should be 12.5 at idle and around 13.2 wot...idle=pilot jet and air screw,wot=main jet and needle

The higher the number the richer correct?

X2 on those settings.

No, the lower number is richer.

so should i drop a size on my main jett to lean it out some? i have a 50 pilot and 167.5 main. running uni fliter w/ billet adapter and dual two brothers exhaust and BRP cdi 2 1/4 turns on a/f screw

I would try a 160 main, and make another run.

we started out with a 45 pilot and 155 main..and that was very close,but elevation has alot to do with it also..higher elevation=leaner jets..its trial and error..takes time to get it right but when u do its great!!

when you make your wot run,you need to run it atleast 300 ft because it may be rich when you first nail it but it might get leaner as you get higher in the rpms..thats what you should be looking at,mine will be 12.8 when i nail it but when i get close to 8000 rpms it will be around 13-13.2

Good point, and if you hit the rev limiter it will throw it off for awhile also. Like redrhino said, "lot's of trial and error"

thanks for the help guys