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Discussion Starter · #1 ·
I was wondering if anyone has ever tried to run a single carb instead of two? Of coarse it would need to be a bigger carb but at least no carb syncing would be needed. Does this sound possible or worth doing to anyone else?
 

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I know a guy who took a CX motor and adapted it to a Cub Cadet to make a racing lawn mower. He welded up an intake and mounted a 2-barrel automotive carb onto it. Not sure if he ever got it going or not, though.
 

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didnt dick in reilgh turn a 500 into a 250 so i would think he only used one carb
 

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our carbs are essentially a double barrel set up which if I was going to use a single carb... I might try.




Then I'd be trying to figure out how to put "Dual" webers on the thing... Oy!
 

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Discussion Starter · #6 ·
our carbs are essentially a double barrel set up which if I was going to use a single carb... I might try.




Then I'd be trying to figure out how to put "Dual" webers on the thing... Oy!


That weber carb does look nice. I'm just thinking. But is it possible/plausible to up the jet size and run just one keihin carb?
 

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That weber carb does look nice. I'm just thinking. But is it possible/plausible to up the jet size and run just one keihin carb?


I think you may have missed my point. Essentially the two carb set up on our bikes is virtually the same as a single double barrel weber. they are progressivly jetted etc... to answer your question more specifically, You could do it, it may work, even work well if you can get enough draft to compensate for the increase in manifold volume and distance. in a side draft app like the CX I think it would be a venture in diminishing returns...
Check out Harley Davidson Carbs for single carb setups on twins.
 

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I dimly recall someone making a manifold and using a single carb as well

but dont recall any follow up on results.

I'm here tinkering right now and just been looking at my bike

I can see a possible snag in that the main frame tube may limit the space

to mount it centrally.
 

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This would look cool as damn getout with the velocity stacks under my seat!







 

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There was a CX500 engined JZR with a single SU carb, I don't know details, other than the owner said it was quite thirsty.
 

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This question seems to pop up every now and then, with most agreeing that it would not be worth the effort to do.

However, a possible alternative that might give some of the characteristic of a single carb with very ittle work would be to fabricate an "equilization manifold" between the two intakes.



Years ago I worked on a CX tech school engine that had a 1/2" or 5/8" copper line installed connecting the inlet ports of the two heads. It looked like the port areas had just been drilled and the line bent to fit and then JB welded in. The idea was that for a cylinder on the intake stroke it would allow some flow to be drawn though the opposite carb - keeping the flow through both carbs more constant and smooth, and increasing the effective size of the carbs. The engine did run on a test bench, but we didn't have a dyno so I can't say if the mod helped or not.



I have seen guys pipe the vacuum sync ports together on sport bikes trying to squeeze more out of the engine, but to me those little ports would be too small to make much difference. This is not a new idea either, I think some of the old 2 cylinder Kawi's I used to work on had some sort of equalizer line between the intake boots, and Yamaha had their YICS system tying the intakes of their cylinders together inside the head.
 
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