750 b4. Front sprocket nut

Can anyone tell me the measurements of the 79 kz750 twin front sprocket nut. Mine came off while riding ( long story) so I thought I'd replace it with a spindle nut. Same thing really. But I don't know the thread pitch. I think the nut was a m20-1.5 but not positive. Can anyone fill these details in for me

Am thinking 27mm is across the hex, and 20mm is the thread. Later KZ's came with a 30mm head on the nut. Both are 20mm thread.

Good Fortune!

What about thread spacing . Is it 1, 1.5, 2? Because different nuts have different thread spacing like fine or coarse. It looks more fine than coarse so I think it's a m20-1.5 ,

Of course you could eliminate any guesswork by getting a genuine part. It is no longer an "Active" part, but they can be found (see 1st link). Also, don't forget to get a proper washer so the nut stays put. The washer is still an "Active" part, so any dealer can get it for you. Partzilla lists it at $2.79 (see 2nd link). Ed

www.nwvintagecycleparts.com/search-resul...earch.x=0&search.y=0

www.partzilla.com/search/?q=92200-1065&x=12&y=10

650ed wrote: Of course you could eliminate any guesswork by getting a genuine part. It is no longer an "Active" part, but they can be found (see 1st link). Also, don't forget to get a proper washer so the nut stays put. The washer is still an "Active" part, so any dealer can get it for you. Partzilla lists it at $2.79 (see 2nd link). Ed

www.nwvintagecycleparts.com/search-resul...earch.x=0&search.y=0

www.partzilla.com/search/?q=92200-1065&x=12&y=10

This is very true haha . These spindle nuts are actually the same nut just a different name. The only issue is the lock washers . I had one on the motor and I'm not sure how the nut came off . Was riding on the highway and just lost all grab. Pulled over and noticed the sprocket front hanging on to the shaft barely. I'll be using some kind of lock tite this time for sure .

I believe it is a physical impossibility for the nut to come off IF the correct washer is used and if it is bent up onto the flat of the nut correctly. This is becasue the washer is splined to the output shaft so it cannot twist on the shaft and if it is bent onto the nut the nut cannot unscrew. Ed

Since there is no nut it should be real easy to just measure the threads.

Metric is measured peak to peak, while SAE is measured in number of threads per inch. You could even use thickness gages (Feeler gages)to measure the thread. in this case rough is good enough so, 1mm = .040" and 1.50mm = .060" while 1.75mm = .070".
Forget all that if you have a metric thickness gage

650ed wrote: I believe it is a physical impossibility for the nut to come off IF the correct washer is used and if it is bent up onto the flat of the nut correctly. This is becasue the washer is splined to the output shaft so it cannot twist on the shaft and if it is bent onto the nut the nut cannot unscrew. Ed

Applies only to new washers, if the tabs are bent often enough they will break off and you'll be coasting down the road.
Been there, done that, bought half a dozen washers from Jeff to solve that problem :laugh:

steell wrote:

650ed wrote: I believe it is a physical impossibility for the nut to come off IF the correct washer is used and if it is bent up onto the flat of the nut correctly. This is becasue the washer is splined to the output shaft so it cannot twist on the shaft and if it is bent onto the nut the nut cannot unscrew. Ed

Applies only to new washers, if the tabs are bent often enough they will break off and you'll be coasting down the road.
Been there, done that, bought half a dozen washers from Jeff to solve that problem :laugh:

I agree 100% ! He needs to buy a new, correct washer. If he does the sprocket will stay on. Ed

I went ahead and bought the correct nut and washer the other day. Sorry I didn't post that haha my mistake . Got them in today and just installed them. Bent the tabs to the nut. Now I only bent one tab and then another across from it . Should I bend all sides?

No; 2 are plenty. I normally bend only 1, but 2 won't hurt a thing. Ed