Topic: "78f motor, "74k frame, '76 swing are and rear wheel? cb750.

[la ca fe]

I am seeing if any of the cb750 gurus here on the forum will know if this set up will work?

[Jerry Rxman Griffin aka MuthaF'er]

The 78 engine will require a 10mm offset to everything to the rear using the frame you have. 

[la ca fe]

I do have a "76f frame as well.
Do you know if the "78f motor's sprocket will align with the rear '76f swing arm and hub?

[754]

 I know that it will not..
 not sure but offset sprocket on front. might fix it.. or change the sprocket carrier on the wheel , move the shock if you can and prepare to cut or change chainguard..

[Don R]

 I'm a fan of the 76 frame and swing arm with the rear disc. But that might just be me.

[Jerry Rxman Griffin aka MuthaF'er]

I do have a "76f frame as well.
Do you know if the "78f motor's sprocket will align with the rear '76f swing arm and hub?

No, that's what I just did.

[riffman12]

76 swingarm and 74 frame will align, the 78 motor will not.

the 77 and newer 750s used a wider chain which required them to push the front sprocket out by 10mm

To make up for this, they had to move the left side of the swingarm out 10mm.

If you really want to make the 78f motor work in the 74 frame, you could buy a 77 or newer swingarm and a wider cush drive for the rear wheel (or a rear wheel from a 77 or newer bike)

There are companies that make offset sprockets and all that, but it's not worth the headache in my opinion.

I tried to make a 77 swingarm work on my 76 750 and it was a giant headache. Ended up just buying a 76 swingarm.

[70CB750]

Yes it will, I have 78SS engine, wheels, swingarm, brakes in K3 frame.  See my signature for the build.