• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

Idle mix unresponsive

Dogma

Forum Sage
Hey gang, I'm just finishing up a carb cleaning and balance before deciding my 850 is ready to sell. Here's the thing: #3 is completely unresponsive to the idle mix screw. I can't kill the cylinder by running it all the way in, and backing it out 5 turns doesn't have any effect either. Idle is a bit rough, and it's a little rough under power at around 2000 rpm. Vacuum balance is even.

My theory is, a slightly PO-munged choke lever (Suzuki terminology for the little dingus on the rail that pulls the plunger out of the carb), is holding the choke circuit open just enough to mask whatever I'm doing to the idle mix. Any other ideas?
 
Nothing jumped out at me when I took it out to make sure the o-ring was there. I didn't examine it closely either. It didn't feel different from others when bottomed. I'll have a close look when I have time to get the tank off again.

I forgot to mention I left it set 2.5 out for the test ride.
 
Last edited:
Have you pulled the plug wire you verify the cylinder is actually firing well enough too make a difference in the way the bike is idling?
 
Have you pulled the plug wire you verify the cylinder is actually firing well enough too make a difference in the way the bike is idling?

I didn't think to try it. I guess because I was trying to kill the cylinder, rather than find out why it was dead. I'll add it to the list.
 
OK, I finally had time to get back at this. Pulling the plug wire didn't change the way it was running (and made about 6 mm of arc). So, the reason I can't kill the cylinder by starving it is because it's already dead, and I'm too deaf to know the sound of a GS running on 3 cylinders. I tried running the screw from bottomed to waaay out (no spring tension) with no change. The point of the mix screw is in good shape, and the new lever on the choke rail has all of that working smoothly. So, it sounds like I need to go back and check the idle mix circuit like Steve showed me Saturday evening ('nother story).

Right?




For reference later, when I've forgotten: With mix screw and pilot jet removed, spray carb cleaner through the screw hole to verify clear passage into the throttle plate area. Cover the hole in the throttle plate area and spray again to verify clear passage back through the pilot jet seat. Use a couple drops of oil and compressed air for this one. Why not carb cleaner again?
 
It's not unusual for a cylinder or two to not have a effect on the engines idle. As long as the bike is running well I don't worry about it.
 
Back
Top