Mlwahler
XS650 Enthusiast
My XS intake nipples( for syncing) are connected to each other with a short hose from carb to carb... I run a peanut tank with gravity petcock... Should the carbs be connected or individually capped off.
-
Enjoy XS650.com? Consider making a donation to help support the site.
XS650.com receives a small share of sales from some links on this page, but direct donations have a much greater impact on keeping this site going.
Carb intake vacuum line nipples
- Thread starter Mlwahler
- Start date
wherearewe
Rub on Ya Titties
I have mine capped individually but either way will block the vacuum and stop air being drawn in from the outside. In the big scheme of things, im not 100% sure but i dont think it makes a major difference.
Last edited:
Jbinnington
XS650 Addict
Are we allowed to use the n***le word???
angus67
Welder's penetrate deeper!!
What word is that? I hope were not being sensored here. TRAVIS!!!!!
I have my vacuum line connected like yours. I had them capped individually, but kept blowing off the caps. It seems to idle a little smoother too.
FWIW, the factory uses them to work the vacuum operated petcocks or on later models with only one petcock, they capped off t'other one.
I used the capped spigot on my Heritage to work my Scottoiler and later capped off the petcock spigot when I switched to a Standard tank with manual gas taps.
But yeah, I see no reason that linking them won't work as well as capping them.
I used the capped spigot on my Heritage to work my Scottoiler and later capped off the petcock spigot when I switched to a Standard tank with manual gas taps.
But yeah, I see no reason that linking them won't work as well as capping them.
First year or so Yamaha linked the two sides with a fairly big diameter tube then quit doing it. 
One end is visible above the cam chain tensioner.
One end is visible above the cam chain tensioner.
Even though Yamaha discontinued this practice early on in the 650's production run, they never changed the casting .......
On a later motor that you have apart, if you were so inclined, you could drill and tap ports for vacuum take-offs. This would benefit JBM manifold users and those who run VM aftermarket carbs.
As far as capping the original nipples on the factory manifolds goes, I've found these 7/32" vacuum caps from the auto parts store fit perfectly .....
Yes, you will want to retain them with a clip of some sort. This old bike likes to occasionally fart or backfire through the carbs, even when in a good state of tune, which can blow the caps off. That's why it's handy that they sell them by the 6 pack, lol.
On a later motor that you have apart, if you were so inclined, you could drill and tap ports for vacuum take-offs. This would benefit JBM manifold users and those who run VM aftermarket carbs.
As far as capping the original nipples on the factory manifolds goes, I've found these 7/32" vacuum caps from the auto parts store fit perfectly .....
Yes, you will want to retain them with a clip of some sort. This old bike likes to occasionally fart or backfire through the carbs, even when in a good state of tune, which can blow the caps off. That's why it's handy that they sell them by the 6 pack, lol.
