• 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.

Warms up then idles up to 4,500 rpm?! '83 GS750

  • Thread starter Thread starter Macmatic
  • Start date Start date
M

Macmatic

Guest
I'm working on getting my GS sorted out and here is where I'm at:

It starts right up with full choke, even after sitting for five days while I was out of town. Wants to idle around 2,000rpm on the choke. Once it get warm enough to idle without the choke it goes down more towards 1,000rpm but then almost always dies out. It sounds slower than 1k too... odd.

Once it gets good and warm (3-4min the gauge starts to come up towards 160) if I blip the throttle it seems to hang up at around 4k when I let off....and just idles there forever...well as long as I let it run anyway.

I've tried using MAPP gas around the carbs and both sets of boots to check for leaks, pushing on the throttle linkage to make sure it isn't hung up, nearly burnt myself backing out the throttle stop screw, set more slack in the throttle cable, tapped on the carb bodies with a hard plastic rod to try and free any stuck pistons (eveything felt fine when I put them together).

Vavles and float heights are set to factory spec. Carbs are newly "dipped" with new internal o-rings from Robert Barr, new intake and throttle shaft o and x-rings from me. I bench synched them before installing with a small drill bit. Air screws are set 1.5 turns out from lighhtly seated.




Any ideas or links to the thread I was looking for but didn't find?

/\/\ac
 
Ok. I don't know how cold starts will be now....or how I fubar'ed this in the first place but the high warm idle was due to the idle control screw being in way too far. I turned that POS back out until the idle dropped to about 1500 and started synching the carbs...

Now I've got 1, 3 & 4 at about 25cm Hg but can't see to get #2 to budge off 12-14cm Hg. The petcock vacuum tap is blocked off and triple checked. I've got a spare set of carbs to look at but I still can't see how to adjust #2 without putting the others way out of line.

/\/\ac
 
Are the 83 750 carbs VM or CV?furthermore does it have one carb that the other three get adjusted to? Ill bet it does, just synch number two to it and then 1 and 4 to those. is the little adjustment screw turning properly? I had one that needed removed and cleaned to get it set accurately.
Is the compression good on all four cylinders? and are the valves set properly? those can affect how much vacuum a cylinder is capable of producing, otherwise its just a matter of getting two set to three, and then making 1 and 4 work on that.
if all else is right they should cold start just fine, mine can sit 10 days and start within a second of touching the button, on a thirty degree day. getting it warmed enough to ride right is a different matter :)
 
Thanks for the input LW,

I see now that the center adjuster kind of makes 2 & 3 "see saw" on the carbtune. Turn it one way and 2 is higher, the other way and 3 is higher....find the right balance....mess around for 20minutes or so trying to tighten the locknut with the right tool...go order the tool and come back to finish the job.

So now all four are within 1cm Hg of the others 1,3 & 4 are even with 2 being very slightly lower. Good enough until I get the adjuster tool!

Tomorrow I'll get some road miles on and see how it looks/feels under load.

/\/\ac
 
You must log in or register to reply here.
Back
Top