• 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.

Vacuum Petcock and CR's.

  • Thread starter Thread starter pontiacstogo
  • Start date Start date
P

pontiacstogo

Guest
I searched but couldn't find a definitive answer.

So I've just realized that the old tank I removed and the new one I plan to use both have vacuum petcocks. I've replaced the stock carbs with a set of Keihin CR33's. What are my options for the petcock;

1). Run it in the prime position and switch it off each time I park (kind of used to this anyway).
2). Tap into a vacuum source somewhere (either fab a fitting in a spigot or use one of the synch. outlets).
3). Buy a non-vacuum petcock (assuming such a thing exists for my tank).

Any thoughts/advice? I guess option #2 would mirror the stock functionality best - if I go that route, where can I source a vaccum fitting? Any downside to that approach?

TIA.
 
I'm not familiar with CR's, I run RS flatslides myself. They don't have sync ports on them, mine do? If you have sync ports on the intake port or manifolds you could pull vacuum from there. With my RS carbs it seemed like the stock petcock wasn't flowing enough fuel so I picked up a Pingel. They have adapter plates with different bolt spacing for different bikes. The nice thing about them is when you turn them off the fuel is definitely shut off. They have them with dual outlets and some have a reserve function.
 
I'm not familiar with CR's, I run RS flatslides myself. They don't have sync ports on them, mine do? If you have sync ports on the intake port or manifolds you could pull vacuum from there. With my RS carbs it seemed like the stock petcock wasn't flowing enough fuel so I picked up a Pingel. They have adapter plates with different bolt spacing for different bikes. The nice thing about them is when you turn them off the fuel is definitely shut off. They have them with dual outlets and some have a reserve function.

I may look into a Pingel but it seems a shame when the petcock I have is near new (and seems to work fine). I don't believe the CR's have a vacuum port anywhere. I have seen folks tap a spigot for a vacuum source but I think that's kinda fugly.

Can I not use one of the 4 fittings in the head (intake side) used for synching the stock carbs? If yes, where would I pick up one fitting?
 
I may look into a Pingel but it seems a shame when the petcock I have is near new (and seems to work fine). I don't believe the CR's have a vacuum port anywhere. I have seen folks tap a spigot for a vacuum source but I think that's kinda fugly.

Can I not use one of the 4 fittings in the head (intake side) used for synching the stock carbs? If yes, where would I pick up one fitting?
That's what I meant by tapping into the sync ports on the head. You can pick up adapters for sync gauges that will fit the ports. Check with Motion Pro for the adapters. You'll just need to find out if you need 5 or 6mm adapters for your bike.
 
Only issue I can think of is that tapping into engine side vacuum is constant while the engine is running, while I think the vacuum source used for the petcock on the mikuni's is before the carbs, so it varies with throttle position. or am I wrong? I am still a newb with bikes...

I still cant see it being an issue as long as your float valve works.
 
Hi Mr. pontiacstogo,

If you really wanted to cheap out, leave the existing petcock on 'Prime' and fit a simple $3 on/off valve below it. But I think the Pingel would be a better solution. Just remember to turn it off when you're done riding. :)


Thank you for your indulgence,

BassCliff
 
Back
Top