• 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.

Bike dies when taking off choke.

  • Thread starter Thread starter gottogochop
  • Start date Start date
what bike is this? I can't tell.
Runs ok on choke? Ignition is ok.gas flow is ok.

CV carbs?
My theory-you pushed the actual jets out? The long ones that the cv slider runs it's pin in? I don't mean the pilot circuit. I don't mean the main jet that you unscrew. It's under that. You must PUSH the main jets out and clean them and all passages that lead to them.

if you haven't got it, from Bass-cliff's site read this.
Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf
 
Hi,

Most bikes this age have several problems. Yours has a couple of extra problems because of the modified intake and exhaust.

These items cannot be stressed enough:

Properly cleaned carbs.
Properly adjusted valves.
Clean and properly functioning charging system.

You will find information and "how to" guides on my little website.

You have the additional joy of trying to tune carbs without first establishing a stock baseline. The Dynojet Stage 3 kit will save you a lot of trial and error.

Go through the maintenance lists in the "mega-welcome" and properly address each item. Skipping steps or taking shortcuts will be frustrating at best and hazardous at worst.


Thank you for your indulgence,

BassCliff
 
gottogochop said:
Started by completely taking the carb apart, spraying the jets with carb cleaner. took a air compressor to the jets. took the jets out, cleaned them with a tiny wire (manual says so).
Click to expand...
This is not cleaning the carbs. You need to either use carb dip or the sonic cleaner, get a set of o-rings from cycleorings.com, and follow the procedure on BassCliff's website. How to rebuild your carbs
 
I'll echo the sentiments about cleaning your carbs,
But you have stock jetting and THAT WON'T WORK with that intake and exhaust set up. (Pods and pipes) you're running very lean. If it in fact did run before, I guarantee you it ran like garbage. And through no fault of your own, you don't know the difference because its never run right to begin with.
Running this bike this way will eventually destroy the motor. Mainly the top end.
The burn is too hot, and it will burn the valves.

You need to rejet. I can give you a ballpark on your set up, but you'll still have to tinker with it to dial it in perfectly. I'm assuming your bike is a 77-79 750. Or was before someone had at thee with ye olde hacksaw :D

Order yourself some 117.5, and 120 main jets. The stock pilot jets will be ok most likely but you may want to order some #17.5 pilots as well.
Get an oring kit from Robert Bar at www.cycleorings.com. You are going to have to completely disassemble the carbs anyway to rejet and move the needle clips so you might as well clean them for realsies.

Post back and we can go from there. If thisis a bit too daunting...PM me and I might be able to help you out further.
 
Okay, I put 105 main jets in, it started with a bump, ran a little bit better. I could take it off choke, but had to really rev it out, or it would die.

I'm going to go way up on the MJ size now. and adjust the needle clip. I also bought an ultra sonic cleaner. which seemed to work well.
The bike is a 78.
 
BassCliff said:
Hi,

Most bikes this age have several problems. Yours has a couple of extra problems because of the modified intake and exhaust.

These items cannot be stressed enough:

Properly cleaned carbs.
Properly adjusted valves.
Clean and properly functioning charging system.

You will find information and "how to" guides on my little website.

You have the additional joy of trying to tune carbs without first establishing a stock baseline. The Dynojet Stage 3 kit will save you a lot of trial and error.

Go through the maintenance lists in the "mega-welcome" and properly address each item. Skipping steps or taking shortcuts will be frustrating at best and hazardous at worst.


Thank you for your indulgence,

BassCliff
Click to expand...

I've narrowed it down to the it being a fuel delivery problem, i'm going to be using the rebuild guide on your website. I just have to find a kit for the VM carbs.
 
Ok, I put a 117 MJ in, it starts without pushing. it was still lean, So I put a 122 in and its a lot better. I just don't understand how one day the bike can decide to quit working with the jets it has. must have been something to do with adjusting the valves. Now I'm only running on 2 cylinders!...must be a bad coil.
 
it may be points or condenser, I looked at someones points they looked fine, he replaced them and it started right up
 
You must log in or register to reply here.
Back
Top