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Diaphragm vents

PostPosted: Tue Jun 11, 2019 11:22 pm
Author: Cusstout 1100
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?

Re: Diaphragm vents

PostPosted: Wed Jun 12, 2019 3:05 am
Author: Flyingdog
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.

Re: Diaphragm vents

PostPosted: Wed Jun 12, 2019 9:21 am
Author: Jake
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.

Re: Diaphragm vents

PostPosted: Wed Jun 12, 2019 8:47 pm
Author: Cusstout 1100
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.