Hi. I have an 03 Pro that won't idle for anything. Had carb off three or four times and cleaned everything. The idle circuit appears clean and I can run wire thru ever jet and hole I can find. The mid and top range seem fine, but the idle is starving for gas. It doesn't race at all, when choke is on, it idles sweetly, but after letting off the throttle it winds down to where it should idle, but quits without even trying. If I snap the throttle right before it quits, I can keep it running, but it has a flat spot ( that is typical of not enough gas).

I have a vague recollection (It's been this way for a year) of the idle becoming less and less reliable, until finally it went away completely.

Could I be missing something in the idle circuit. Could an intake leak cause this problem but not display any other symptoms? Could a clogged pipe cause anything like this. Other than refusing to idle, it is asymtomatic of any other problem

I love the bike...it's amazing, but I'm ready to give up on it and go look for an old Yamaha..

I'll be grateful for any help you can provide. .

A 12 year old Pro, first thing I would do is pull off the mag cover. Grab the flywheel and move it vertically for play. Any play would suggest mains and seals. Also are the vents to the carb clear and where do the hoses route to.

Edited September 27, 201411 yr by lineaway

Yikes! Can you help me understand how mains and seals would affect the idle but (apparently) not anything else? I checked the play I. The crank when I got it two years ago and there was no radial play, but more axial than I'm used to seeing on my

While I was going thru other posts, I thought if a few more details:

I'm in the Midwest USA, and bought it from someone also in the Midwest.

When I first got it, it ran much better. ( I wouldn't say the idle was spot on, but it was close) I'm a little paranoid to go to 100:1 mix and I (used to) ride it to work (@3 miles) , so I run it at about 80:1. When I ride it at higher RPM for any length of time, it smokes a lot. I chalked it up to the fact that its usually run at low rpm, but I retrospect, probably points to mains and seals.

Thanks for your insight.

It still could be something else, but that is where I would start.

Thanks. I checked the vents and found two, one on each side. They are connected together by a tube with a hole cut in the bottom of the tube.

I'll check the crank play ( hopefully tomorrow)

The vents are correct then.

1 Idea

Check the floats in case they have fuel in them. This has the effect of drowning the bike but gets better as you open the throttle and let more air in.

Also loads of standard stuff like air filter, spark plug etc. Mine started to be a bitch to start before eventually finding a .8 plug gap which should have been my first check.

Keep going the answer is there somewhere.

what happens when you adjust the slide height , also how have you set the mixture screw ,,, how about having the carb ultrasonic cleaned

Thanks for all your help.

Update:

No evidence of radial play in crank

Air needle adjustment makes no difference

Slide height (raised all the way with screw) it'll stay running, but it's like having the throttle open 1/4.

I like the idea of the ultrasonic. I think that'll be my next move.

Will update next week.

Thanks again all

Poor compression , damaged reed valve . Partially blocked jets

What carb is on the bike?

Too much oil on the air filter choking out the engine? Clean the filter with gas and let it dry out and then put it in the bike with no oil on it to start her and see how she runs.

It sure sounds like a plugged idle jet circuit to me. Clean, clean and clean some more. Soak or ultrasonic, then blow compressed air through all holes in both directions.

What size and type of carb is it ? give all the letters.

OK...

I finally got to the 280 this weekend and soaked the carb body 24 hours in carb cleaner and then blasted it with about 120psi air. It runs like a champ. Thanks to all for your advice and encouragement. (1st carb I ever had to do like that. I think I'll do 'em all that way from now on. Way better than trying to poke wires thru. ).

The pilot actually has two holes in the carb body that it blows through. Straight up to the slide and out in front of the slide. I`d bet the later was blocked. Good job!