cb750 carbs

[f2005bsbll]

Ok Guys Ive Started A Project And Am Trying To Save As Much Money As Possible. I Have A 450Rebel Bobber And Am Used To Working On It So Dont Know Much About The 750. The 750 I Have Is A 76 And Ive Come Across Some 1977 Carbs For Cheap And In Awesome Condition. Will These Work And If So What Kind Of Difference Am I Looking At? Im Putting This Motor On My 450 Frame When I Get Everything Done, So I Just Need It To Work Awesome, I Dont Mind Extra Work If It Requires It To Make The Carb Work.

[TOOLS1]

You will need the 77-78 carb boots, and cables. Other then that it's a bolt on. However you are not going to get much of a performance increase. I prefer the older round top carbs myself. A lot easier to work on.
TOOLS

[shinyribs]

As far as all out performance increase-probably not. But they do have the accelerator pump feature which the roundtops don't have. Low rpm throttle response is supposed to be better with the accelerator pump. No personal experience here,but it makes sense. Also, it is actually easier to start a cold bike with the accelerator pump carbs. Being able to squirt a dose of fuel in there rather than waiting for a cold engine to draw it in. Again,makes sense to me.


That said I'm still running roundtops. Super easy to work on. Deadly reliable. Cold starts are not that bad at all with a properly tuned bike which is very easy to do with these machines. If I ever build a kick only bike I'll use 77-78 carbs simply for easier cold starts.Otherwise roundtops do just fine.

[Lucky 1]

I think it is a bad idea.

It sounds like you want to put 1977 CB750 carbs on your 450 rebel bobber?

Isn't the rebel a twin cylinder?

It sounds like a nightmare and someone out there would really like to have those
1977 CB750 carbs because they have the adjustable slide needles.

You sell the  1977 CB750 carbs and get the carbs you need.

The Honda Rebel uses twin /dual 29.3mm carbs.

[Black 750K8]

Lucky I didn't read it that way looks like he is putting a 76 750 motor on his 450 frame and wants the 77 carbs for the 76 motor.

[shinyribs]

f2005bsbll wrote

 I Have A 450Rebel Bobber And Am Used To Working On It....... So Dont Know Much About The 750...... The 750 I Have Is A 76 And Ive Come Across ..... Im Putting This Motor On My 450 Frame When I Get Everything Done

Holy S*$(!!! I missed that part!!

PLEASE DO THIS!!! That would be one heck of a fun bike!! Pleeeeeease do it and post up a build thread. Pleeeease?!?!?!

[Black 750K8]

I hope he is a good welder. The word gusset comes to mind. I don't know what that rebel motor ways.

[f2005bsbll]

The Motors Really Aren't that Different In Size Or Weight. of Course The 750 IsBigger And Heavier But The Height And Length Are About The Same Size. The Difference Comes Into Play With The Width. The Frame Should Hold Up And If I Can't Tackle It I Have A Local Shop That Wants To Do It.

[Lucky 1]

That also sounds like a bad idea.

Weight of engine not compatible with the frame or suspension.
Chain may not line up with out engine being offset.
The electrical would have to be changed.
The CB750 is a dry sump system. Where would you put the oil tank and hoses?

The brakes may not be good enough to stop the extra weight.
The exhaust pipes my not clear the frame.

Tire size of the 450 Rebel not compatible with the extra weight.

[Black 750K8]

The Motors Really Aren't that Different In Size Or Weight. of Course The 750 IsBigger And Heavier But The Height And Length Are About The Same Size. The Difference Comes Into Play With The Width. The Frame Should Hold Up And If I Can't Tackle It I Have A Local Shop That Wants To Do It.


Then I say go for it. I have been on a bike with a 350ci motor but the frame was made for it and I'm thinking you can make it work just be safe and make your dream come true. As far as what Lucky is talking about this is a custom bike every detail will need to be worked out. But you know that.