carbueration

[ManagerMike]

Been thinking in the back of the modification lobe of my mind about fabbing an intake manifold to fit one carb to feed all four cylinders. No sync worries, adjust idle speeds and mixtures by ear, been done for decades on other bikes and cars.... carb selection for something in the 1200cc range. whaddya think...
Let the thread war begin.....

[b.walker5]

Been thinking in the back of the modification lobe of my mind about fabbing an intake manifold to fit one carb to feed all four cylinders. No sync worries, adjust idle speeds and mixtures by ear, been done for decades on other bikes and cars.... carb selection for something in the 1200cc range. whaddya think...
Let the thread war begin.....

This was discussed a little while ago on here. Do a search for the thread for the answers, but my preference would be a side draught weber or couple of sidey dellorto's. Plumbing would be interesting but completely doable IMO.

[crazy steve]

That would be this thread: http://www.xs11.com/forum/showthread...le+carb+intake

Biggest hassle IMO would be getting a manifold design with reasonably equal runners.

[81xsproject]

That's ONE of the past threads discussing this topic . The biggest problem in my book would be dealing with the loss of POWER! To put it relatively, there is a reason single throttle bodies don't hold a candle to port injection.

[ManagerMike]

Maybe two carbs? Naw, that would be silly, right?
Just throwin this idea around, seeing if it might just bear fruit.....

[cywelchjr]

Just go all the way to go EFI like 81xsproject. It's part of my future plans. What I hope to do is also incorporate either vacuum advance or a knock sensor to provide ultimate timing control.

This is assuming that a knock sensor or vacuum advance control is possible. I would think that would give the ultimate in fuel economy. Well, combine with the 750 FD mod to go with it.

[natemoen]

Just go all the way to go EFI like 81xsproject. It's part of my future plans. What I hope to do is also incorporate either vacuum advance or a knock sensor to provide ultimate timing control.

This is assuming that a knock sensor or vacuum advance control is possible. I would think that would give the ultimate in fuel economy. Well, combine with the 750 FD mod to go with it.

geez why don't you plumb in some nitrose as well and really go all out!

[cywelchjr]

geez why don't you plumb in some nitrose as well and really go all out!

It's not about power, it's about mileage, tunability and hopefully in the long term reliability. I don't expect it to be an easy road, but not having to worry about the choke, or fuel overflowing, or (you get it).... But the primary is smooth running and good fuel economy, and with good EFI the computer will compensate for varying fuel quality automatically, as well as compensating for altitude and such if done right. Plus if you have a laptop with you it's possible to tune on the fly as I understand it.

I mean I'm looking forward to getting to that point and tinkering with the settings to get it just where I want it and all, and then once it setup I want to be able to walk out and know it will start with the first tap of the starter button (oh, wait, it does that now ). I'm not complaining about my gas mileage now, but being able to break into the low to mid 40's certainly has some draw. If it gets a little bit more power, fine, but that is NOT my goal, it's to be able to tune it without having to pull the carb bank and tweak things. Frankly I HATE carbs! Didn't like them in high school, and nothing that has happened to me since then has made me change my mind. Nothing made me happier than getting rid of all my carburated cars. Don't get me wrong, I'm pretty good at cleaning and adjusting these carbs (haven't done the 11's carbs, but my 400 has the exact same carbs except for the jetting and slide springs and I've rebuilt and adjusted those extensively) but that doesn't mean I like it. Getting everything smelling like the cleaning solutions and getting sprayed in the eyes is not fun (ok, I wear glasses so that helps but you know what I mean).

Fortunately my daily rider is unlikely to need that kind of work. Since it's working really well and I ride all year round it's like a car that's driven all the time. How often did you do carb work on a regularly driven car? Pretty much never right? Same applies to a bike with the exception of having the touch up the balancing/sync and such because of things moving because of the greater vibration on a bike. Otherwise, if the gas never sits in it long enough to cause a problem, and you run some cleaner through it once in a while, it will remain pretty trouble free. On the other hand, bikes that sit through the winter, will generally need the carbs cleaned every year, unless pains are taken to properly prep things, and that doesn't always work either. For me, I'll stay where I am for now, and ride year round and not have to clean them, but the 400, when it comes out of mothballs I'm gonna have some work to do on it.

[natemoen]

I know I was just joking Cy. I wouldn't mind EFI either but at the time I know o can't do it. But perhaps in the future.

[81xsproject]

The MS EFI uses the Speed Density fueling algorithm which, at it's base, uses a MAP (air pressure in the intake manifold) vs. RPM. The ignition timing uses the same thing, so vacuum advance capability is built in.