Forum Donations
Search
VTF Google Search
 Click Here

Diaphragm vents

Technical Virago Help Topics
  • Advertisement

Post a reply

Diaphragm vents

PostAuthor: Cusstout 1100 » Tue Jun 11, 2019 11:22 pm

Yamaha saw fit to have a separate vent tube/filter for each carb diaphragm, each going to "calm air" . I'm wondering what would happen if the two were "T'd" together into a single filtered tube (into calm air somewhere....). Maybe there'd be some interference between the two diaphragms? Or maybe if the carbs were well balanced there would be no problem? Thinking about eliminating the right side pod and maybe simplifying things a bit by joining the two vents into one.

Thoughts?
My Ride, '97 XV1100, +14, 10" over forks, progressive rear, Jardine forward controls, cobra slip-ons, K&N Filter, Dyno Jet Stage 1, Kuryakin grips, heat demon heaters, custom fabricated seat, chrome side covers, bullet signals, risers, custom modified rear fender with modified FZ1 tail light, sectioned and reversed front fender, custom paint...

Image

Cusstout 1100
Silver Membership
Silver Membership
 
Posts: 951
Images: 7
Joined: Mon Oct 17, 2011 4:37 pm
  Flag
Bike year & model: 1997 xv1100 Virago
1987 xv535 Virago
1985 xv1000 Virago

Re: Diaphragm vents

PostAuthor: Flyingdog » Wed Jun 12, 2019 3:05 am

Well.."I" would think it should work. Long as the volume of air is sufficient to keep the same equal diaphragm pressures as oem. Nice idea, but somewhere under the saddle? Not lotta room to squeeze another hose thru that opening the fuel lines are threaded thru. :bg: Thought about eliminating the pods, every once-in-a while. But every-time I do, I always think this engine set up looks sooo skinny in the first place, the pods "kinda" off-sets that look. Unless I went with some harley-esk air cleaner gizmo on both sides. (Not).. :ops: Besides: Got an air scoop under my right pod. MY left pod holds all my wiring/fuse blocks and it's been ages since I've fiddled with redoing and balancing the look of everything that works well as is. If you get my drift. Definitely tell if you try it.
User avatar
Flyingdog
Silver Membership
Silver Membership
 
Posts: 2804
Joined: Fri Jun 23, 2017 2:31 am
Location: Colorado Flag
Bike year & model: 1985 xv1000 Virago
1981 xv750 Virago
Sex: Male

Re: Diaphragm vents

PostAuthor: Jake » Wed Jun 12, 2019 9:21 am

Cusstout 1100 wrote:Yamaha saw fit to have a separate vent tube/filter for each carb diaphragm, each going to "calm air" . I'm wondering what would happen if the two were "T'd" together into a single filtered tube (into calm air somewhere....).


On the surface, that sounds like a good idea.

The vent tubes are a specific size, I assume that those sizes are relative to the volume of air that each carb diaphragm needs to function properly. Now you take that particular volume needed and cut it in half when you tee both together ( assuming you join both to a same size hose ) and you could potentially have a problem.

Now, if you tee them together to a larger hose, that would theoretically work, at least in my way of thinking.
_______________________________________________________________________
“It ain’t what you don’t know that gets you in trouble.
It’s what you know for sure that just ain’t so.”

~Mark Twain


There is an old Chinese proverb - "Man with one watch knows the time. Man with two, not sure."
User avatar
Jake
Mod
Mod
 
Posts: 12552
Images: 108
Joined: Wed Jun 06, 2007 3:18 pm
Location: Penn's Forestland otherwise known as Pennsylvania Flag
Bike year & model: 1996 XV750
Sex: Male

Re: Diaphragm vents

PostAuthor: Cusstout 1100 » Wed Jun 12, 2019 8:47 pm

Yeah, that makes sense. The OEM hoses are about 3/8" in diameter, so .... according to Pi and the squared radius, a 1/2" tube should be pretty close to double the size, and flow capability. I'm going to see what I've got kicking around here; maybe I can come up with something reasonable that I can tuck in under the tank. This is not on my 1100, it's an '85 750 (dare I say the word "chopper") I'm working on. I'm sticking with the ol' Hitachis for now, an Adam Smith single may be in the future. So no side pods, and possibly velocity stacks for now if I can find some "shorties" that look decent.
My Ride, '97 XV1100, +14, 10" over forks, progressive rear, Jardine forward controls, cobra slip-ons, K&N Filter, Dyno Jet Stage 1, Kuryakin grips, heat demon heaters, custom fabricated seat, chrome side covers, bullet signals, risers, custom modified rear fender with modified FZ1 tail light, sectioned and reversed front fender, custom paint...

Image

Cusstout 1100
Silver Membership
Silver Membership
 
Posts: 951
Images: 7
Joined: Mon Oct 17, 2011 4:37 pm
  Flag
Bike year & model: 1997 xv1100 Virago
1987 xv535 Virago
1985 xv1000 Virago



Post a reply


  • Advertisement

Return to Virago Help "Tech"

Who is online

Registered users: dazthebiker