My '85 Odyssey seems to be running lean when at an idle. The stock 32mm Keihin has a 142 main jet with the needle at the stock setting. Here are the symptoms:

1) When cold, it won't idle on it's own for more than 15-20 seconds without stalling out.

2) Once warm it's idle is very racy, applying the choke a little bit brings the idle down to where its supposed to be. As soon as the choke is released it idles right back up though.

3) The plug is burning medium to dark brown, which tells me that the main jet isn't to lean.


What is the quickest way to remedy this problem? Bigger idle jet? ( If there is such a thing. ) Change the position of the clip on the needle?

Thank's Eric

 

It's funny, I read your post once. Then again to make sure I read it correctly. You answer your question in the first sentence. "My Oddy seems to be running lean" Yes it seems to be. Have you tried to adjust the airscrew??? Try that first, I would try going in with it, less air, more fuel. If that doesn't seem to affect it at all. R&R the pilot jet one or two sizes larger. You'll have to remove the carb and float bowl, it's recessed right next to the main jet. Good luck...

 

Main jets have nothing to do with idle. They basically affect jetting from about 1/2 to full throttle.

Since you say the odddy runs better with the choke on, I'd agree with
Backcountry -- adjust the airscrew. Start by turning it all the way in. Then come out 1 1/2 to 2 1/2 turns. This should be about right.

If this doesn't solve the problem, two other things to look at:

1: Gunky carb. Clean out the carb. Pay special attention to the little needle and seat which are actuated by the floats, if they show signs of wear, they have to be replaced.

2. Air leak.

Hope this helps.

Pam

 

Thanks Backcountry and Pam. Backcountry you where correct, I did know it was lean I just wasn’t sure of the best way to solve the problem. I'm going to try what you and Pam have suggested this weekend. Pam it's good to see you back here and posting again!

Why does the service manual say to never touch the airscrew unless the carburetor is rebuilt or disassembled for cleaning?

Could the low-speed lean condition cause low end bogging when accelerating?

Thanks, Eric