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I have a CMX-450 from 1986 under deep modification. One of the idea is to go for a single carburetor. Does anyone know a Y collector that could fit the Rebel two cylinders
 

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You would have to make one and you would loose hp and be hard to get mixtures correct
 

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There is no 2 into 1 intake manifold for the 450 at least I have never seen one but often thought about it. What carburetor would you be think of using?
 

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Here is a pic and short video of my second 450 with single carb. Waiting on turbo to come back, long story but had a hose failure that would occasionally stop oil flow to turbo. No video of it with turbo, but will once I get it back next week. These are while I was still working on battery box and wiring. So ignore all those.
 

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When you said your bike was under deep modification you mint it.
Does that carburetor have an adjustable main jet?
I have found installing an air/fuel ratio gauge to be invaluable when doing carburetor mods.
 

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Yes, the main jet, how did you plan on jetting that carburetor for the 450 Rebel engine?
 

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I did build it as an adjustable main jet and it currently has a 150 main in it. It runs good with the turbo and I have not ridden it without the turbo, so jetting without is only on the stand. With the turbo, I get about 35 mpg and run around a/f of 12.5 at 8# of boost. If I beat on it, I get 20ish mpg. I can change mains fairly easy with it on the turbo, since it hangs out over the back in case the main needle does not make enough difference. This is a draw through setup.
 

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Sounds good, A/F ratio of 12.5 will make about full power and keep the engine cool enough to live.
 

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Made from left over tubing laying around.
Hey Mod Adahy you did a great modification, running on Turbo !!!
I am modifying my Rebel 450 in a Bobber/Sporty like (see sketch here after) and I would make the distribution system little bit more simple, hence the idea of single carb, but with a more steep feedback on the throttle opening. For this last (Old School) I was thinking to a Mikuni 42 flat throttle valve and external air intake.

How manifold you did works with respect to the fact that you have 2 different lengths of the intake ? Could I ask what carb you have and which jet you used when running without Turbo on stand?
 

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I did not worry too much about different runner lengths as a lot of current cars run slightly longer runners, although I did put a small baffle just past the the first runner to help divert or supply some resistance to any fuel in the intake. I run a lot of the Keihin 42mm butterfly carbs because they are so easy to build into adjustable main with needle. I run the same main with or without the turbo on the stand since it is almost never on the main anyways or atleast there is no load to worry about.
 

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Single carb, no turbo made 31.8 hp at the rear tire. Made 32 runs on the dyno yesterday. Over 53hp @ 5# of boost with the turbo.
 

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Outstanding improvement in HP on just 5# of boost and man that is a lot of runs on the dyno -- congrads!
 

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So I wanted to dyno it with and without a muffler, so I made one. For the test, I only run the muffler without the turbo as the turbo acts as a muffler anyways. took about an hour and made completely of stainless steel. Body of muffler is 4" and made ribbed inserts that are essentially straight through. Only cost me 1.3hp.

 
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