• 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.

VM29SS Carb Tuning

  • Thread starter Thread starter Gearz
  • Start date Start date
G

Gearz

Guest
About a year ago, I swapped a set of RS34 carbs for a set of VM29SS carbs. I was told they are pretty rare and are a good performing set of carbs (basically 4 TM33 carbs with a 29mm bore racked together.) My bike is 79 GS750l with pods and a 4-1 exhaust. I have no idea how to tune these carbs. Has anyone messed with these or messed with the TM33 at all? The bike is trying to start while cranking the starter, but it just won?t fire up 100% and take off. I put on a Pingel fuel valve and I know I have great fuel flow.

I appreciate any any help at all.
 
Did you clean the 29s and replace the O rings and gaskets?
 
Well the person I bought them from (someone from this community) said they gave them a good cleaning and that the jetting should be very close to what I need. So I am taking their word for it. My next step was to go over the timing again and then I?ll crack into the carbs and check them out. But do these carbs have adjustable mixture screws on them?
 
Adjustable idle mixture screws, yes, just like most motorcycle carbs

The fact that the bike won't start indicates fuel isn't going thru the carbs

I'm working from the assumption that the bike ran fine before you swapped carbs
 
Yes, it ran with the RS carbs on it. It hauled at higher rpms, but ran awful down low. I?ll pull them off and check them out to rule that problem out.
 
How are you going to check the Tiny passages in the carb body?
 
I don't know that much about the VM series carbs, but the 750 came with VM26 carbs. Jumping up to 29s (sleeved-down 33s?) seems to me that you have too much carb for the engine. Even with "proper jets", you may not have enough air speed through the venturis to get the right mixture.

I could be wrong, actually, I hope I am.
dunno.gif


.
 
Back
Top