Notchey shifting transmission

[Twtex85]

I was wanting feedback from other CB750 owners about how smooth their transmissions shift. Mine is a1975 750k and is a little notchey sometimes when shifting. I’m running a 10w-40w motorcycle specific oil and am wondering if other people have had this and if they were able to change to either a different oil brand or a single weight oil and saw an improvement.
Any feedback would be appreciated.

 

[dirtdigger]

They are not the smoothest shifting, 50 year old technology isnt as refined as modern bikes. If you have a certain gear that is bad it could be bent shift fork or worn shift drum.

 

[Twtex85]

Thanks. It is not any one gear in particular. I notice it going into either 2nd,3rd, or 4th. Sometimes it is fine but other times not. I think I am going to try some 10-40w Honda GN4 oil and a little zinc additive and see how it does. From what I have read the higher zinc level oils can make a difference in the shifting and are beneficial overall for these old motors.

 

[pickleknuckles]

Thanks. It is not any one gear in particular. I notice it going into either 2nd,3rd, or 4th. Sometimes it is fine but other times not. I think I am going to try some 10-40w Honda GN4 oil and a little zinc additive and see how it does. From what I have read the higher zinc level oils can make a difference in the shifting and are beneficial overall for these old motors.

Higher ZDDP (zinc) while good for flat tappet engines can also mess w/a wet clutch setup.
There are ways to modify your clutch hub for better oiling and better oils without additional ZDDP or Moly.

I added the oil passages and use Valvoline 4-Stroke 4T 20-50 for wet clutches w/a CycleX 5 plate clutch and couldn't be happier.

Hondaman clutch mod links -
https://www.sohc.co.uk/index.php?to...e hondaman clutch,the stock ones, cheers Mark.

http://forums.sohc4.net/index.php?topic=7190.0

CycleX 5 plate clutch -
https://www.cyclexchange.net/Engine Parts Clutches.htm

Oil -
https://a.co/d/8zZGOAi