Topic: Exhaust header difference

[Johnny5]

Does anyone know what the difference is of the diameter size of the early and late CB750 exhaust header where it mounts to the head?

[scottly]

The early 750 had spigots (short tubes) bolted to the head, that the header slipped over. If you are trying to bolt a late exhaust onto an early motor, I think you can just remove the spigots, install studs, and use all the late hardware. By the way, don't even try to remove the flat-head Philips spigot screws without an impact driver!

[Johnny5]

The early 750 had spigots (short tubes) bolted to the head, that the header slipped over. If you are trying to bolt a late exhaust onto an early motor, I think you can just remove the spigots, install studs, and use all the late hardware. By the way, don't even try to remove the flat-head Philips spigot screws without an impact driver!

Actually, Im trying to find out if it's possible to do it the other way around. I can stand the late model mounting hardware and find it much easier to mount exhaust onto the early model heads with the spigots. And yeah, I took some spigots off a head and my impact driver worked very well.

[scottly]

The I.D. of the early header is the same size as the O.D. of the spigot. The I.D of a K7 pipe is about 28.6 mm.

[Johnny5]

The I.D. of the early header is the same size as the O.D. of the spigot. The I.D of a K7 pipe is about 28.6 mm.

Awesome, thanks!