• 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 Port

  • Thread starter Thread starter cberkeley
  • Start date Start date
C

cberkeley

Guest
I decided to purchase the four gauge sync instrument from Z1 Enterprises after I did a little experiment with an old auto vacuum gauge and a restrictor valve made from a refrigerator ice-maker water inlet valve. Gave a good and stable readings at the intake vacuum ports. Maybe a more expensive gauge later on, but for now the Z1 kit.
However access to the inner intake ports proves to be a PITA especially cyl-2, so I devised this nifty (IMO) port (machined and polished from a billet of aluminum) and although it is not finished or installed yet, this would provide easy access to the four ports right on the side of the bike (see pic below). Of course the access screws will all be changed to SS Allen head bolts. But you get the idea.
Making this has lead to another simple great idea (IMO) and may prove to be a performance enhancer but more info on that later (need to do some testing before getting too much egg on my face).
View attachment 1766
 
Just got the 4-gauge set from Z1 Enterprises. Ok, it's not great but it's not half bad either. I found that they can be calibrated quite well if you have another trusty vacuum gauge handy. Put all five vacuum tubes into the hose of a vacuum cleaner (yes five, the four from the Z1 gauge plus the one from your rusty-trusty calibration standard). Stuff the vacuum's opening with a plastic bag. The plastic bezels of the gauges easily unscrew to give access to a calibration screw on the gauge faces. Start up the vac and adjust the four screws for a reading that matches the calibration standard.
The little restricter valves that come with the gauges do not setup the calibration they are merely adjustable dampers to mitigate the effects of pulsations from the cylinders.
Be careful with the calibration screws they are soft so a good fitting screwdriver is a must. They are also quite prone to movement from vibration, so once they're calibrated to your liking, a microscopic dab of loctite (I used a spec of Crazy Glue on the tip of a pin) in the area where the screw-head meets the meter-face keeps them in place and allows you to break the "set" for adjustments at a future date.
Will do my carb sync this weekend.
 
Ok, so I've finished my nifty vacuum port which gives me easy access to the carb intake vacuum ports for synchronizing and experimenting (see photos below)
View attachment 1826
Have not done the carb sync as yet but testing the gauges on it, it works perfectly. What I did learn is that my carbs are in fact out of sync. In fact carbs 1, 2 and 4 are not to much out of whack from each other, but carb 3 is some ways off (too open). The Idle is not bad at all and I've been using it that way all along.
So I just could not resist connecting carbs 1 and 4 and 2 and 3 together to see what happens.
...... Wow! it smoothed right out, in fact it's the smoothest idle I've ever had.
Can't wait to ride the bike like this tomorrow.
On the weekend I will do the following:
1) Sync the carbs properly.
2) Plug all the ports and try the bike (normal config.)
3) Connect 1 and 4 and 2 and 3 and test again
4) Connect all ports together and test.
5) Report on my findings.
Man this is fun! :-D
 
Hey Buddy...just can't help but smile when reading your posts and thinking..."this guy is one of the sharper tools in the shed". If all goes well with this design, you may want to market it! \\:D/ Looking at what you've done, the only way you could get it to balance any better would be to do the sync! That or have all the lines run to a "central port" within the vacuume block. I like it...I really like it! :-D
 
Motorcycling has become the most complete hobby for me, tinkering, thinking-up new stuff, meeting new people, exchanging ideas, learning new stuff and if that's not good enough ....there's riding the machine through the countryside.
Thanksfor your sentiments.
 
It's 5:45am and I've already been out for a test ride.
No adjustments have been made to the carbs so they're still out of sync as previously mentioned and vacuum ports 1 & 4 , 2 & 3 are linked. Here's what I've found from the test ride:
1) Smoother Idle
2) Less engine Vibration at all speeds.
3) Very smooth throttle transition from idle to top end.
4) Going back to all ports plugged Roughens the idle, there's noticibly more engine vibration and the throttle response is not as smooth.
5) Busted my tach cable on the ride.
6) I think it's the first time I rode and returned home without bird crap on the face shield.

Ok, items five and six above not related to the test.

Seriously I'm quite impressed with the results so far and here's what I anticipate.
a) With the carbs synced and the vacuum ports plugged, the engine should run as smooth as described above.
b) Linking the ports with a properly synced rack of carbs, should dynamically negate any transitional imbalances in vacuums between the carbs and help ensure smoothness.

Will continue the experiments and report. This is so easy to do. :-D
 
Last edited:
? How did you make your hose connecter? Did you find one that was just that size or did you have it milled for you?
 
After reading your other thread on this same topic, I bought some hose t'other day and intend to try linking 1&4 and 2&3 as well. Have you tried linking them all together yet?
 
How the hell did I miss this post?

That is absofvckinglutely cool as all get out Cletus!

If you could make a system that allows adjustment of the throttle bodies as well on the same block, that would be about the coolest mod I have ever seen. As it is I love it. Brillient!
 
t3rmin said:
After reading your other thread on this same topic, I bought some hose t'other day and intend to try linking 1&4 and 2&3 as well. Have you tried linking them all together yet?
Click to expand...

Yes I did manifold all the tubes together and there's no measurable or discernible difference to 1&4, 2&3. And since just doing 1&4, 2&3 gives smoother, equalized performance over just plugging each port, simplifies things and looks neater, I just stayed with it.
 
Jethro said:
How the hell did I miss this post?

That is absofvckinglutely cool as all get out Cletus!

If you could make a system that allows adjustment of the throttle bodies as well on the same block, that would be about the coolest mod I have ever seen. As it is I love it. Brillient!
Click to expand...

Dude ....I thought you saw that already and dismissed it as Cletus fvcking with the bike again. :-D
 
bcrowther said:
Cool. I want one!!!
Click to expand...

Easy enough to make yourself, even with hand tools. Thought about making them and offering it as an accessory but the damned brass nipples are so expensive at $5.00 each needing 12 pieces they would cost more than the manifold block, SS Allen bolts, standoffs and tubing combined
 
You must log in or register to reply here.
Back
Top