• 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 Take Off Adaptor For Carb Balancing

  • Thread starter Thread starter EvilEnfield
  • Start date Start date
Thinking about this more, maybe it helps keep the vacuum pulses in sync as the intake valves on those cylinders open?

Here's my thinking: syncing the carbs ensures they all pull the same vacuum, but you still might have a slight difference in the timing of the vacuum pulse based on valve wear and valve clearance. Linking the shared cylinders would "even out" the pulse and get air/fuel into the cylinders at the same time. Based on the power band, the GS valve lift/valve timing is engineered for best performance at high RPM, so it might make sense that the most impact is seen at lower RPM.

Actual experts, please correct me if wrong.
 
Sometimes you really don't have to have the technical reasoning to know it just works. I plan on giving this method a shot. it's a very cheap mod, and ANYthing to get the mpgs' up is golden in my book.

Thanks for the tip, I'll chime in and give my results...
 
back when i did stuff with the old Dneprs/Urals and K650's its the same trick we used, running an adapter plate with a nipple for 8-10mm vacuum line between the two cylinders, it gave more bottom end torque and power, which is quite nice when you are running 900+lbs bikes with a taller rear diff gears. Also, some with dual carburetor air cooled VW's, same principal. But with VW's it all depended on which carb you ran, as some of them ran like (__!__) with a sinc tube in between.
 
Last edited:
willie said:
When you've finished synching them, I suggest you use them to connect manifolds 1 with 4 and 2 with 3. I bet you'll be glad you did. ;)
Willie
Click to expand...

WOW ! ! ! Day and night difference. I just did this to my 750 and SO smooth in the bottom end of exceleration... Can't believe they didn't come this way stock...

Thank you very much for this tip Willie.
 
Now if you were to add a Hayden Krank Vent Plus to the Crankcase vent, You would gain twice the benefit to what you have just done. I am also seeing a significant mileage increase even running at high speed flowing with commuter traffic. At the price of gas today the valve will pay for itself in a relatively short time since I ride almost every day.
 
Last edited:
Google Hayden Krank Vent Plus. There are vendors where you can get it for less than directly from Hayden. I got mine for $105.00 including shipping. One word of warning. Split the valve opened and look at the rubber umbrella valve. If it has JAMES in raised letters, it is a defective valve. James makes the valves, but the ones Hayden uses are not marked and work very well. Replacements are about 75 cents. We got two over here in Virginia that Hayden replaced immediately. It's most likely better to order it directly from Hayden, and save any possible angst (125.00). Here is a link to my setup. Directly off of the vent (and you would want too if you have a stock air box) the valve accumulates a bit of white jell in the return ports that would require periodic maintenance. The further away the better, mine is next to the clutch housing. https://picasaweb.google.com/lh/photo/_MvxW6LDOn49LEIbcLrf8GbBBlRZwJM0tdWO15A5B6s?feat=directlink
 
Last edited:
Here is Hayden's link. Disregard the horse power claims, they are after all designed for first generation Harley Evolution motors. It works best on the low end on inline fours. I noticed as much difference adding the valve as I did after crossing 1-4 and 2-3 with vacuum lines. Since you have seen the same you could appreciate the difference. The up to 6 mpg increase in my daily commute gas mileage was a real bonus. http://www.haydensm6.com/kvp.htm
 
"sedelen", he obviously got a Hayden valve with the defective umbrella valve that somehow slipped through. They have JAMES in raised letters on them. Hayden will replace them. The unmarked valves that they use do work, and rest assured that I would not post any results of something I use if there was any question in my mind that it didn't work. My valve and my friends both failed closed like the one in the thread you mentioned (talk about fogging down the neighborhood). Hayden was more than helpful in resolving the issue. The new umbrella valve works with no issues.
 
Crazy_Russian said:
back when i did stuff with the old Dneprs/Urals and K650's its the same trick we used, running an adapter plate with a nipple for 8-10mm vacuum line between the two cylinders, it gave more bottom end torque and power, which is quite nice when you are running 900+lbs bikes with a taller rear diff gears. Also, some with dual carburetor air cooled VW's, same principal. But with VW's it all depended on which carb you ran, as some of them ran like (__!__) with a sinc tube in between.
Click to expand...

Man I love Urals etc.
 
One would think that they would have batch numbers and recall the bad ones instead of making it the end-users responsibility...
 
They are trying to trace the problem as we speak. The umbrella is simple to change, they know the umbrellas with the raised James stamp is a defect and will send the new part. There is nothing wrong with the valve body, just the rubber valve or whatever it is made of.
 
Spyder said:
WOW ! ! ! Day and night difference. I just did this to my 750 and SO smooth in the bottom end of exceleration... Can't believe they didn't come this way stock...

Thank you very much for this tip Willie.
Click to expand...

Always glad to help. ;)
I'm looking forward to reading about your experience with the Hayden Krank Vent Plus.

Willie
 
ALL of the Pro Stock cars & bikes use electric vacuum pumps to create a vacuum in the crankcases. This increases ring seal & makes more power. This also lets you use lower tension rings for even MORE power & still have good ring seal. It WORKS!!! On a GS motor it is good for 4-5 horsepower & WILL pull oil out of the motor if placed wrong or you have too much oil in the motor. Just so you know, P/S bikes only use 2 quarts of oil in them. Ray.
Click to expand...
"willie", "sedelen" pointed out a thread to me and I found this quote by "rapidray". I guess the Hayden valve is producing enough vacuum to be beneficial without being too powerful, three to five lbs. I am getting much better gas mileage and the bike is a "silky" performer at low speed. By the seat of my pants it also has a lot more power, but I'm happy to settle for what I can measure, and that's better mileage!
 
OV66, thanks for copying the info posted elsewhere by RapidRay. I had read it when he posted it, but reading it again was a good reminder. I think I mentioned elsewhere that I had my reservations when you commented that your way of connecting the vacuum lines was far superior to the way the PO had connected mine. I did it when I got home and became a believer. My buddy, Doug, who you met at the WV Rally, was so impressed with the difference that he did the same thing on his ZRX and had similar results.
I'd like another "review" of the Hayden Krank Vent Plus ONLY because of the cost involved. Otherwise, I'd be the one providing the review. Also, its hard to believe the bike could have even smoother low speed performance. Your bike must be all the more impressive now. And, 4 the record, I'm being sincere not sarcastic.
Willie
 
Thanks willie. The Hayden valve gave me as much of a change as you noticed on the 1-4, 2-3 vacuum crossover mod. There is no doubt that it works and Ray's explanation of what vacuum does for the pro stock motors and ring seal makes a lot sense, except this is working on a smaller scale. The placement comment he made also, sort of falls, in line with what I see. When I had the valve connected directly to the crankcase vent, I got a milky jell build up of oil and vapor in the relief ports behind the umbrella valve. Placed down by the clutch housing, all you see is an almost clear white film with no buildup of oil being sucked out. Of course, this is a one way valve and not a pump. This and the vacuum crossover work together to really refine these motors on the low end and most likely through the entire power band, but not as noticeable. The price is a little steep, but the replacement umbrella valve is only about 75 cents and the valve body is a lifetime design. Installation is simple, so if we ride together in the future, You're perfectly welcome to try it out. The increase in mileage will pay for itself in a short time. This seems to be still improving, the last tank under the same driving conditions is up from 36.5 to 42.5 mpg.
 
Last edited:
So if I read this right all you have to is leave the sync adapters on an just connect them with some hose and I should have better low end response as well as better overall engine operation? Maybe I will try it.
 
You must log in or register to reply here.
Back
Top