1978 kz1000 police bike. Why does it only go into 1st gear, then back to neutral?

SOURCE: What type of oil does my 1978 Harley Davidson shovel-head use?

60 wt (50 if hi temp under 50f)

SOURCE: 1991 suzuki swift

• Try moving the shift lever up a notch or two. This will help eliminate any accidental lifting of the shift lever by the shoe. No cost to try this one.
• Your bike has a shift drum index wheel that holds gear positions. The spring may be weak on the index wheel arm. This is the low cost attempt a solution to the problem.

• The other potential problem is a slightly bent shift fork. It may only be barely engaging into first gear. This is the more expensive of the three potential solutions.

SOURCE: BMW R1150GS 8 years old, 5700 miles. Trouble engaging 1st gear

It's a problem thats common in the Adventures and I think it has to do with the driveshaft set up. I generally let clutch out slighty when kicking it down to 1st and that does the trick. I dont think there's anything mechanically wrong, just one of those glitches in the design.

SOURCE: Pops out of 1st gear under acceleration.

Hi Buddy
There is not an easy solution to your gearbox problem,it is general wear on the 'dogs' or 'shift drum'..The only other thing it could be is wear on the 'external shift mechanism'.
I,ve just rebuilt a 1996 vn1500 classic whitch had the same problem so if you need any advise or step by step photos please email me at '[email protected]'
paul

SOURCE: my 1996 kz1000 police bike is leaking oil from the shifter side

hi buddy is it leaking oil from the shifter shaft or the left side casing if its the casing its the gasket gone or if its the shaft its the oil seal gone get back to me and i will tell you how to do it