Keihin Carb Choke ???

[dalton125]

I have a RM 125 that I put on a PWK 35 Air Striker Keihin Carb on. It runs great finally after I got the jetting figured out, but upon first start and I engage the choke lever up, it idles really really fast. So much so that you want to hurry up to get the choke off to make it idle normal again. Is there an adjustment to the choke/idle speed? The base idle is fine and I don't want to hamper that at all. Any thoughts or help would be greatly appreciated.

 

[cr2504life]

My bike does the same thing,

 

[marcusgunby]

You can just pulse the kill switch to keep the revs down until it settles.Its a very common thing you see alot on the boards, a richer pilot will help but it maybe less crisp when warmed up.

 

[bclapham]

just out of interest, what jetting and needle you running?

 

[dalton125]

Funny you should ask about jetting, After much advice that was wrong from Sudco, I found that the main that works best for me is a 160 main, I have a 48 on the pilot and a DEK (1464T) needle in the middle position for the clip. It still may a little to rich on the idle to 1/4 throttle, because I am out about 2 1/2 turns on the screw. It ain't too bad though, but might start to load up on the plug if I don't get on it every 4 or 5 min or so. It will have to do until I get around to get a leaner pilot. Sudco said to start with a172 main, a 60 or 62 pilot and a DGJ needle 1 up from the middle. I did and boy was this thing rich. So rich that I felt like I should plant a tree or two to make it up to plant earth for the damage to the ozone that I was doing. Dalton125

 

[mylesc]

My 97 CR250 did the same fast idle at cold start up thing when I switched to a Keihin PWK-AS. The bike had a new top end, new crank seals, and held pressure during a leakdown test. It startled the crap out of me the first time it happened. Other than the sky rocket idle at start up the bike ran flawless and didn't seem lean.

I tried the next size up pilot (58) and it helped the idle at start up but it was too rich when my bike warmed up. I went back to a 55 pilot and just use the kill switch to kill the revs a bit until I can reach the choke to turn it off. From all the posts that I've read it's not uncommon for this to happen at start up.

 

[dalton125]

Thanks it makes me feel a little better, even though a really good carb could be perfect if it were not for the one thing. I would think there would be a engineering change to address this overly fast idle on choke. Maybe I should do it and patent the idea and then sell it back to Kehien. What you think anybody want to go into business? Just kidding.

 

[darringer]

My 99 cr250 does the same thing. I just use the kill switch to keep the revs down until it's warm enough to run without the choke. About 20 seconds. Tried running the next size pilot, also. Fixed the problem, but also ran a little rich aftrer warming up. I went back to the smaller pilot because the bike runs more crisply.