Topic: 1974 Crank into 75F Cases

[mixstup]

Hi guys

I am in the process of rebuilding my 75F supersport motor to be able to race in vintage class up here in Canada.I was wondering if I could fit an earlier 1974 crank (free !) which I intend to have lightened and some spanky new rods. My cases are back from the beadblaster but the original crank shows too much wear to be of any use.
 
Thanks

Mick

[Jerry Rxman Griffin aka MuthaF'er]

Exactly what I did except I used a 78 K crank. That let me get the crank done before tearing my engine/bike down. Sent it to APE for Jay to wave his magic wand over. It came back a lighter, more balanced individual with 4 new friends by the name of Carrillo. I read the journal sizes off of the crank and recorded them before I shipped it. Taking those and my case letters I cross referenced the bearings and ordered accordingly. When I plastigauged it I was very pleased. They all came out at .00015. 

[mixstup]

Thanks Jerry

Ive been following the Rattlesnake thread but didnt want to hijack it!

Is the 78k crank the same as the 74 then?

Mick

[kos]

All cranks will fit any CB750 made, save for the automatics and yes, you can put them in also, with some attention payed to the primary drive! And you can even run a DOHC crank with a lot of work.


KOS

[754]

If you EVER see one with smaller alternator bolt threads, put it aside.. only came on the first 220 or so motors in 69.

 Early ones (not sure till when) have setcrews sealing the drill holes for oiling the crank, later ones have peened balls.

[scottly]

 Early ones (not sure till when) have setcrews sealing the drill holes for oiling the crank, later ones have peened balls.

I HATE it when my balls get peened!!

[mixstup]

Thanks for the replies...I ll post up some pics as im going

Cheers

mick