1980 CB750 Cafe Build (First one)

romieromes

New Member
Hello All!

I'm new to the forum, and this is my first post :) I wanted to start out by thanking the whole community on DO THE TON! I wouldn't have been able to get my cafe build where it is now without the wealth of knowledge that is posted here.

First up, I bought a 1980 CB750K with 37,000 miles on it last year. It ran like crap, needed the choke to be pulled about 1/8 inch to run. Decided to give it the Cafe treatment. I've been working on it for almost a year now. It's taken me a long time to get money for parts and get it all together. Also this is my first experience working on a bike (or any motor vehicle for that matter).

Anyways I've put a LOT of parts into this bike, and I have spent countless hours working on it. I finally have it all together and it starts! Here it is
OfENLu3J

But it isn't running right.

I have a Dyna 2000 ignition on it and new Keihin CR29 carbs. It starts up ok but the choke is utterly useless as it seems to flood the engine. Once hot it idle's fine. But when I drive it, it starts to bog out at 3,500 rpm. It bogs out if I hit the gas hard to. Feels like the timing is off and the carburetors are not properly tuned.

Does anybody have any advice on how I can get it running properly? Has anybody set the timing on their CB750 with a dyna 2000?

I live in MD right between Baltimore and DC. Does anybody know of any shops that could set the timing and tune my carbs for me? Can anybody tell me what the process is for tuning this thing. Does it need to be put on a dyno? or can it be done accurately in a simple garage?

I'm afraid that this might be beyond my skill set, but I've gotten this far, I might be able to finish it!
 
Did you do any work on the carbs while you were fixing it up? The problem that you're describing sounds just a bit like carb floats that are set too low. So you're running out of fuel when your engine needs it.
 
Is it bogging or cutting out? If it's bogging then you have too much fuel, if it's cutting out then you don't have enough? Do those cr carbs have adjustable needles? Check out cb750c.com genesound is a member on there that is extremely knowledgeable on these dohc bikes and with smooth bore carbs and dyna ignition systems.
 
Hey man,

There are a handful of guys here in the DC metro/Baltimore/Frederick area. We could probably get together and get this solved over a handful of beers.

If you are looking to have a shop do it. I would recommend Kapitol Kustoms based out of DC. A relatively new shop, but good guys that can take care of you.
 
Just signed up as a member and saw this thread.

I recently bought an 80 model 750 super sport, all stock, and I'm about to move to Fredericksburg.

Are these shops still around? I'm currently going through all the carb nonsense as well as electrical. Would love to have some brains to pick


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