My idle is so rich, I have to shut the air screws to get it to idle.

I put a 2003 airbox on my 02 650 with a twin air filter a couple of weeks ago. It was runninig like a top before this.

As soo as I installed the 03 airbox, the 650 began idling extremely rich, and would only run right with the air screws shut. [img]i/expressions/face-icon-small-disgusted.gif[/img]
However, above idle it runs like a top. Runs at least as good as it did before.

I checked for stuck choke. Nope.
I checked for rubber flap block. Nope.
I checked the diaphram hose (wouldn't cause this, but I checked it anyway).

I proceeded to remove the air filter with it running and it leaned out and stalled. I adjusted the air screws and they wanted to be right about 3 turns out (it idled great at that point). What gives? Too much pj1 in the twin air? Wrong, because that would flood it at higher throttle (and it runs fine at higher throttle).

It still runs great, even wheelies in high range (even with the 26" tires). I even wheelied the longest wheelie ever today.

Can't figure out why my air screws need to be closed. [img]i/expressions/face-icon-small-mad.gif[/img]

The next thing I am going to try is use the official "Twin Air filter oil". But I am not confident that that will solve the prob. Who knows?

 

Are the pilot jets the same size on both years?

Jeff

 

Yup, they are identical. Same P/N, and both are #40.

However, the carbs are different P/N. But, the stacks on the top fit exactly the same way, same holes, same everything. I'm still stumped.

 

Just a thought, but have you checked the flux capacitor?[img]i/expressions/face-icon-small-wink.gif[/img]

 

maybe you have entered the wrong date in the time travel proccessor![img]i/expressions/face-icon-small-smile.gif[/img]

have you noticed a difference with the new airbox when it does run?

 

Nyroc,

Is this question going to be on the final exam, cause I think I slept through that part of the class.

Seriously, why don't you switch back to the original '02 box and see if the problem goes away. This would verify that it's definately a problem with the new setup and not something that got screwed up in the switch. Let us know how you make out and we'll brainstorm from there.

Steve

 

The idle circuit is very sensitive to a dirty/over-oiled filter. Did you pull the filter out and put the lid back on the airbox? Was it the same or better w/o the filter? If you turn the pilot screws all the way in, you have effectively shut off the fuel supply from the idle circuit. If so, you're getting fuel from somewhere else. There's no way that the choke cable is mis-routed and holding the enrichener pistons up a little bit?

 

It is possible that I over oiled the filter. I used PJ1, and it is probably way too gooey for a twin air. I used PJ1 on my stock filter the first time I cleaned it, and this did not happen, however I noticed a power loss. I got a K&N after that. The guys on the car forums are all pretty much against K&N now, lets more dirt in than foam. I sold my K&N on ebay.

I'm not used to oiling the twin air. It didn't look like much was getting on it, but I must have soaked it.


Nova, I ran it without the filter, with the airbox lid installed and it ran fine. Screws were tuned 3 turns out. I double checked the choke too. The choke would not do this, it usually gets one cyl and not the other, plus, it would screw things up without the filter on. I am gonna order the right filter oil from twin air. My cycle store only carries one product, PJ1, which has the consitency of hot bubble gum. My brother's 400 Priairie runs rich with this crap too.

My quad is quite clean right now. Carbs are clean too. I can't see dirt doing anything like this. The airbox is clean (new) and I have a new diamondG snorkle. Must be the foam oil I used (or the amount).

 

The Twin Air filter comes wrapped in plastic. You did remove the plastic wrap?? Sorry, couldn't resist!!! [img]i/expressions/face-icon-small-smile.gif[/img]

 

Nyroc,
Try this, take STP oil treatment it is rather sticky by itself but very thick. Mix it with some diesel fuel or kerosene just enough to make it sticky but thick as original, then spray that on the filter let it dry well before installing.I use this system all the time rather than all the sticky stuff on the market.

Next I remember you using DJ needles with the Keihin jets take a look at the needle to see they are worn where the needle touches the jet. You may have to replace the needles I have found the DJ needles will wear as the angle is not the same causing the needle to actually cut off flow to the carb. Just an idea I know the same happened to me I changed the needles to Keihin again with a slight modification to the upper part of the chanfer on the needle itself. Give it try it might be worth a look see.