selector forks

Hi, I am having trouble with the transmission on the KZ650 1979. I am working from a 1977 workshop manual and it is saying that there is a difference between 4th and 5th gear forks. I checked mine out and they are both the same, they are stamped with a figure 5 on each of them.The bike when I first got it from USA rode very nicely and nothing wrong with the gear changes and selecting neutral. Sometimes I can get it into 1st gear and back to neutral and sometimes I can get it into 2nd but not very often. Just wondering if it would be better if the bike was running, but I don't want to assemble it if there is any chance of it not being correct

Looking at CMNSL the selector forks are dependent on model and year, some have two different forks and some have two the same. I guess ultimately if it selected ok before strip down then I don't think the forks are an issue. There is no syncro-mesh in these transmissions so if the engine and trans are stationary then it's normal that it can't select gear unless the engagement dogs are aligned.

Unless you can't get 2nd when the bike is moving there is nothing wrong with your gearbox as your statement that it was ok before when you rode it indicates.
These engines ( just like the 900 and 1000 etc ) are fitted with a neutral finder which prevents 2nd from being selected at a stand still.
The 2nd gear lockout is centrifugal and the only way 2nd ( and the rest of the gears) can be selected when the bike is stationary is if the output shaft is spinning such as running the bike through the gears when it's on the main stand.
 

Thanks very much for the info, I thought I had done something wrong, the 2 different forks had me especially when both mine were the same. thanks once again

If working from a 1977 manual note, MANY subtle differences between the 1976-77 KZ650 that won't apply to Your 1979.

On this rebuild of a 1978 model the shift forks were the same :

 

I only have one 1977 model year engine but the bottom end is not split so I could not tell you if it has the two different shaped shift forks.

This may be something that Kawasaki moved away from because it was not necessary and possibly confusing. First model year bikes always seem to be unique in the parts selection and mostly goes away in subsequent years for cost savings or simplification.