2 into 1 intake manifold

I ran a 25 pilot and a 195 main 1 1/2 turns out on mix screw.turn the idle screw all the way out if it idles down ok if not check the the cable just make sure the slide is comming all the way down.did it run ok with stock carbs,?? if so make sure the slide is comming down all the way the cable piched under the tank can pull it open a little.
 
I actually adjusted the cable to have a little but of slack before pulling the slide up just to make sure it wasn't cracked open. Wasn't able to run it with stock carbs, got the bike as a project bike.
 
I'm also having this discussion with pamco Pete in another thread seeing if it could potentially be the timing. But the rectifier is good. And from the things I've read it seems like with a PMA and pamco e advancer ignition, it is a pain to kick over or doesn't kick over at all if it isn't timed. But after I jetted the carb it kicks over first try with ease so I'm assuming it has to be pretty damn close, is that a correct assumption?
 
Just seeing this thread now... Ive been making these manifolds for a few years. I run them on 3 of my own xs's, and have sold a around 15-20 of them.

Im sure you guys covered alot of info about 1-2 intakes so ill spare the details.

Intake_mani_xs650_black.jpg


xs_650_Intake_01.jpg


xs_650_Intake_03.jpg


And a customers scoot...

customer%2Bintake.jpg
 
Looks cool but what is the advantage over a dual 34 set up?
With both cylinders moving together, does 1 carb provide enough air flow for both cylinders? What size carb is it like 42mm or something?

Hi Bob,
the big advantage of having only one carburetor is that you don't have to balance two of the bastards.
And you only need one because only one cylinder at a time sucks on it.
 
Hi Bob,
the big advantage of having only one carburetor is that you don't have to balance two of the bastards.


And you only need one because only one cylinder at a time sucks on it.


If that were true, why do all Japanese and most European multi cylinder engines have multiple carbs. Syncing is no big deal especially with only 2 carbs, that seldom if ever go out of sync as they are on common linkage.
 
[/B]If that were true, why do all Japanese and most European multi cylinder engines have multiple carbs. Syncing is no big deal especially with only 2 carbs, that seldom if ever go out of sync as they are on common linkage.

Hi jim,
because most folks believe that the extra few top end horsepower that multiple carbs give to racebikes translates to multiple carbs giving better low end and mid-range performance to a street bike.
And compared with a single carb, balancing 2 carbs is a bother, balancing 4 carbs is a hassle and balancing 6 carbs is a nightmare.
 
Well I can't argue with that logic - Simplicity.

I wonder what the loss in performance really is. I converted a Virago 920 to single carb, never rode with the dual carbs to compare.
 
Hi Bob,
the big advantage of having only one carburetor is that you don't have to balance two of the bastards.
And you only need one because only one cylinder at a time sucks on it.

Actually not that I know of. A regular XS650 engine both pistons travel at the same time. Only a re-phased engine has alternating strokes for the piston. So on a stock engine both pistons suck at the same time.

Maybe a VM34 carb flows twice the air of stock carbs?
 
Actually not that I know of. A regular XS650 engine both pistons travel at the same time. Only a re-phased engine has alternating strokes for the piston. So on a stock engine both pistons suck at the same time.

Maybe a VM34 carb flows twice the air of stock carbs?

wrong ...the do rise and fall at the same time. But as one is drawing in air and fuel one Is on a power stroke. They fire alternately. Pretty obvious when you follow the valve adjustment procedure. It works very well on triumph and bsa twins even more so because the carb is centered. That's why lots came from factory with it.
 
Actually not that I know of. A regular XS650 engine both pistons travel at the same time. Only a re-phased engine has alternating strokes for the piston. So on a stock engine both pistons suck at the same time.
- - -

Hi Bob,
um, it's a 4-stroke. Suck-squeeze-BANG-blow, remember?
With a 360º vertical twin each pot sucks when 'tother goes BANG, eh?
Mind you, I'd want to stay with twin carbs on a 270º/277º re-phased engine because those uneven induction pulses might confuse a single carb setup.
 
Picked up intake from CounterBalanceCycles as well. Hopefully have a vid running this spring.

5a4c28a8b3a911e3bbef121e54b44c78_7.jpg


I know another guy online planning to sell a shorter version to fit between the stock xs seat post

10882059_767664489987827_1018323007_n.jpg



Just seeing this thread now... Ive been making these manifolds for a few years. I run them on 3 of my own xs's, and have sold a around 15-20 of them.

Im sure you guys covered alot of info about 1-2 intakes so ill spare the details.

Intake_mani_xs650_black.jpg


xs_650_Intake_01.jpg


xs_650_Intake_03.jpg


And a customers scoot...

customer%2Bintake.jpg
 
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