Topic: Cb650 Header/exhaust swap with 92 750?

[Quinnn]

I'm building a1985 cb650 and want to know if I can do a header/exhaust swap with 1993 cb750. I have measured the header spacing and upper cylinder head and everything seems to be the same. I'm swapping to the 750 because it has a custom one piece welded exhaust system that has been shortened and baffled professionally.

I have no problem fabricating new mounting brackets for the exhaust. I just want to know if the headers will fit. Thanks for all your help!

[bryanj]

Wont fit

[pekingduck]

I'm curious why it won't fit.  Did someone actually try it?

An 85 CB650 (dohc) should have similarities to the last CB750, as they are from the same engine family, and share the same bore spacing, cylinder head angle.

[bryanj]

[1993 750 is a totally different beast, engine angle is different and from memory exhust ports are splayed different. People have tried sohc 750 and without lots of mods they wont fit

Anything can be made to fit anything with hacksaw, welding time effort and swearing but there is a point where you ask WHY

[Alan F.]

I just looked it up on the Nighthawk forum, while exhaust port angle and spacing are the same or close enough between the 91-08 CB750 and the 84-86? CB700SC & CB750SC, the spacing on the DOHC CB650SC is different. Elsewhere in the world the DOHC CB650SC was called the CBX650 maybe that will help you to find something.

If you're out of options you can always chop and cut and weld until it fits the way you want it to.
Honestly I'd do a few and keep the best for myself, the others can go on eBay or sell on a forum to other DOHC CB650SC or CBX650 owners, that way the whole venture is zero cost.

EDIT: specified DOHC CB650 models.

[pekingduck]

Just to be clear, Quinn has the DOHC 1985 CB650SC with the 16 hydraulic valves, not the SOHC CB650SC 8-valve model, correct?