4into1

[cb500bobber]

Has anyone heard or know of anyone doing a one carb for a four cylinder.

[Owen Nevins]

I have heard of a kit fir a goldwing, but the cylinder layout on a goldwing is very different. I think the issue is that all the intake tubes from the carb and the cylinders must be the same length. I know this is an issue on carbs in cars, with how sensitive 4 cylinder bikes are it may be a quite difficult task. I'd love to see it done.

[dannyboy]

This is a fairly common modification on GL1000 and GL1100 Goldwings. A place to look at it is: www.randakks.com/TechTip43.htm There he talks extensively about it.

A friend of mine did it on his 'wing and it was a complete pain. He had difficulties getting the jetting correct and eventually machined his own jets to work (he happens to have a complete machine shop at his disposal).

In theory it is a really cool thing to do and if you want to have a cool look it is worth it but most times you will not get much if any performance improvements.

[wlb]

Is this what you had in mind? I just happened to find this website and saw your question. Back when the Arabs turned off the gas tap in the 80's (If I remember correctly) I made up a 4 into 1 manifold from welded tubing to try to improve the gas mileage of various motorcycles. A friend of mine saw it and made up patterns to cast the manifolds from aluminum (much neater than my welded one). We had manifolds for 900/1000 Kaws, 650 Kaws, 750 Hondas (upper left in the photo) and 500/550 Hondas (the other three). I don't have any of the Kawasaki models left but they were quite similar to the 500/550 Hondas. We used a single 34 mm Mikuni round slide carb. Gas mileage on the 550 Honda was 78 mpg at a steady 55 (the national speed limit at the time). They actually ran very well with no visible mixture difference on the spark plugs or piston tops. Mid range torque seemed to be improved. On a stock 1000 Kaw top speedometer indicated speed was 135 mph. With the 4 into 1 top speedometer top indicated speed was 115. From 75 up to top speed acceleration seemed a little slower. Top speedometer indicated speed on the 550 Honda fell from 120 to 110 mph with the 4 into 1.

I used one on a three wheeled car powered by a 1000 Kaw engine and had one on a 1000 Kaw street bike for over a year. It sure made tuning a lot easier.

Attachments:

[A65L]

Nov 5, 2012 16:13:18 GMT -4 wlb said:

Is this what you had in mind? I just happened to find this website and saw your question. Back when the Arabs turned off the gas tap in the 80's (If I remember correctly) I made up a 4 into 1 manifold from welded tubing to try to improve the gas mileage of various motorcycles. A friend of mine saw it and made up patterns to cast the manifolds from aluminum (much neater than my welded one). We had manifolds for 900/1000 Kaws, 650 Kaws, 750 Hondas (upper left in the photo) and 500/550 Hondas (the other three). I don't have any of the Kawasaki models left but they were quite similar to the 500/550 Hondas. We used a single 34 mm Mikuni round slide carb. Gas mileage on the 550 Honda was 78 mpg at a steady 55 (the national speed limit at the time). They actually ran very well with no visible mixture difference on the spark plugs or piston tops. Mid range torque seemed to be improved. On a stock 1000 Kaw top speedometer indicated speed was 135 mph. With the 4 into 1 top speedometer top indicated speed was 115. From 75 up to top speed acceleration seemed a little slower. Top speedometer indicated speed on the 550 Honda fell from 120 to 110 mph with the 4 into 1.

I used one on a three wheeled car powered by a 1000 Kaw engine and had one on a 1000 Kaw street bike for over a year. It sure made tuning a lot easier.

So where would I be able to find one of the Honda 500/550 manifolds now. Do you still have them? Ebay?

[wlb]

You might find a setup used. The three 500/550 Honda manifolds in the picture are the only ones that I have left and I do not have the carburetors or air filters. I do have the special slide springs that are required for the 34mm carb and throttle cables. Unfortunately I do not remember what internal parts (slide cutaway, main jet, pilot jet, needle) were required for the carburetor to make it run right.

[tango911]

yes theres a couple companies that do a 4-1 carb and a 4-2 carb setup. ive worked on the later.

[tango911]

Here is the 2-4 setup