Topic: CB750F and K interchangeability query?

[canoscan]

How much of the bike throughout the series is interchangeable between the different version K1, K2... F1, F2 etc..

In particular can you fit a CB750K rear chrome mudguard onto a CB750F instead of the plastic rear brake light housing?

Can you take for example most of a CB750F and change it back more towards a K with the fuel tank, seat etc.

If possible just how easy is this to do?

[cobra2411]

Tanks interchange easy. The seats don't as the hinges are different. F seats lock on the right side and K's lock on the left. The back half of the frame from the shock mounts back is longer on an F. It's about 11" from the shocks on an F and about 8" on a K.  Theres a hoop that ties the left and right frame rails together that's different but from memory I think the holes for the front mud flap/ inner fender are at the same point - in other words the 3 extra inches are from that point back to the grab bar mount.

Not all the F's have the big plastic mud guard - or it's missing from my 76... My 78 has it but I haven't looked at how hard it would be to delete. 

The passenger peg triangles are different, the K's are symmetrical, the F's aren't. The F2/3's don't even have them, they use aluminum mounts for the rear pegs and rear master. Also the F2/3's use a 3 bolt battery box.

Oil tanks are different and don't interchange and the kickstand mount is farther back...

[Don R]

I built a 77k into a drum brake F. Only because we had the parts already and felt the need to create a bike using what we had. Welding is required. Not recommended for beginners on a budget. It got named  F'nK!

[canoscan]

I noticed too late that many people are asking similar questions.

Yep, welding is way beyond me.

So it's a pretty bad idea trying to buy an F model with the plastic rear (which I notice are significantly cheaper here in the UK) and trying to make it into a K then.