Topic: What carbs would you use on a 1974 CB750?

[rruser]

We have a 1974 CB750 that needs intake boots and carbs. If I understand the service manual... the change in carbs after 76/77 was in size and a accelerator pump on carb #2.  As long as the right intake boots are used (larger boots for larger carbs) should there be any problem using the newer style carbs on an older engine? Rejetting/tuning is not a problem but we would rather not have to mess with making something fit that shouldn't.

While on the topic, would going as far as 1980/81 carbs with the vacuum based slides be any better? I only ask because some of the later model carbs can be found in better shape and cheaper (sometimes)

Thanks.

[cd811]

my opinion...
the later carbs are better but...
the problem is adapting carbs and boots to head.
the late model (77 up)boots  are a little too big for the head but I've been told that they tighten down with clamps just fine. I think the late model are better because they have an accel pump, but I just wasn't crazy about the fit so I'm running early carbs on my 73. cv carbs would be even better but even more problem to adapt.
If money is no object and you want to do it right...
www.dynoman.net sell boots for$200+ that will allow you to bolt mikuni 29mm smoothbores right up!!   

[Lumbee]

...I think most would not call the 77/78 carbs superior.  In fact many would say they can be a little tougher to deal with than the older style.  Either way I think u'd be better to stay with pre 77 carbs.  Parts are pleniful, and once they are tuned I think u'll be pleased with the results.

[rruser]

This is more of a project bike so we are looking for the best bang for the buck. The problem is that a lot of 76/77 and later carbs show up on ebay. A few early model ones show up too but not as many.  I guess if cheap late model carbs don't work I can always resell them on ebay.

Have any of you followed the CB900 fuel injection discussions on http://www.cb1100f.net ?    They got some pretty cool stuff going on there..

[dusterdude]

if you want to change,i think the twin mikuni setup for 500.00 is ideal.i forget who the outfit is thats selling them tho

[cd811]

I believe it's cycleexchange

[dusterdude]

yep,thats it