Topic: Shift drum/shift forks/clutch K7 to K0

[AshimotoK0]

I have two sets of shift drum/shift forks/clutches from  a CB750 K7 (one is from an F1) in good condition. My '69 K0 has these parts and they look in reasonable condition but the bike had done 46k miles and I never saw it running. Will the later parts fit my K0 and were they improved in later years?  For example one clutch has a dual plate and they both have steel rings around the outside of the clutch drum. Is the gear shifting any better with the later shift drum/shift forks?

 My plan is to fit the later parts if possible and keep the genuine K0 parts, just in case I ever sell the Bike (not likely!) I am sure you engine gurus out there must have tried the swap!!!!!!!!!!

[lordmoonpie]

If they are physically the same dimensions then you should be able to drop them in. Things to measure and compare are length of main and layshaft. Distance from bearing centres to end of shaft and the shaft centre mainshaft to shaft centre layshaft distance.

If these are all the same on K7 and K0 they'll be a straight replacement. I'd be confident saying yes to K0 and anything up to K6 but would have to measure K7 parts to know for sure...

[nteek754]

Like lord said up to 76 a sure yes, but where  the 77s went to the differant front and rear sprockets (630) . Would give me some concern but I really think they would be the same. Hey call your local dealer and have them check part numbers I bet they will be the same number. good luck Craig in Maine

[Tower]

The K7 clutch and the K0 have many differences.  Parts are not interchangeable unless they are grouped together.  There are several combinations that will work.

The clutch went through two major redesigns from K0 to K7.  The most significant changes were a) retaining rings were redesigned, and b) clutch centre lengthened.

For example, if you want to use the K7 baskets, then you must also swap out the pressure plate, lifter piece and clutch cover, clutch centre, retaining ring, and switch disk orientation - essentialy replace the whole clutch and covers.

On the other hand, if you want to use the K7 disks, then simply replace them.  The single thickness plates will also swap out, but not the double thickness (without other changes) or the outermost plate and ring.

[AshimotoK0]

Very informative answer - just what I was looking for - Do you know if F1 clutch is like K7 or more like K0-k6

[Tower]

The F1 clutch is closer to K7 than K0.  It probably still has the shorter basket like the K0 since the longer basket was introduced partway through 1975 production.  But, like the K7, the F1 has better springs, better clutch centre, similar disk assembly, and no retaining rings.  

More parts from the F1 than the K7 are interchangeable with the K0. (unless you have the long clutch version of the F1 clutch)

Edit:
Clutches were redesigned several times as I mentioned earlier...
K0 - Clutch A (retaining rings, short springs, short basket)
K1 - K5, F - Clutch B (no rings, short basket, medium springs)
K6 - K7, late model Ks, F2 - Clutch C (new cover, lifter, long basket, double plate, long springs)