not shifting out of neutral

I picked up an 81 kz550 last night. Bought it as a Christmas present for my brother. Bought a new battery and spark plugs, and she started with choke on. Unfortunately, I cannot get it to shift out of neutral. What should I do? Any ideas what the problem could be? The shifter moves easily, just doesn't change gears. Stumped.

Common complaint for newbes. It won't shift into second unless it's moving. (safety feature)
Steve

With the engine running - pull in the clutch and push down on the shift lever. It should go into first gear. Ed

Had the engine running, won't shift. Foot lever feels real loose compared to my 03 shadow spirit 1100

Is the shift lever too loose on the shaft?
Steve

After putting it up on rear kickstand, I find that to shift I need to push the shifter in towards the crankcase With a fair amount of force before it will engage and then it will shift. The problem is that this is not really feasible while riding. How do I fix it?

Possibly. How do I tighten it?

There's a pinch bolt on the rear of the shift lever, if that's tight and there is no slop present between the shifter and the splined shaft the issue could be internal (behind the trans door)

I would do a basic clutch adjustment first & probably replace the cable in case it's stretched or worn.
Note: when doing the adjustment, turn the clutch release adjusting screw counterclockwise first until hard to turn, then clockwise 1/4 turn. some manuals are ambiguous as to which direction to turn it.

Also, maybe change the oil & oil filter, warm it up, get it in first or second gear & take it for a spin over a rough road or RXR tracks if possible, in case the clutch plates are stuck together or something. The problem is probably the shift mechanism, though.

The Kawasaki service manual should have a laundry list of things to check in the troubleshooting section.
Not the 550 manual, but the following site has the 81 KZ650 pdf in the Files section. jarlef z650 . The troubleshooting list is near the end, chapter 8. The 550 is probably similar so the things to check would probably be the same.

Take the lever off and look at the splines. I've had to widen the pinch gap so it would clamp down on the splines tighter. I use a longer hardened bolt. Longer in case it breaks and you can screw it out.
Steve

My 81 550 FSM has a misprint on the clutch cable install. There is a small supplement area for the 1981 A2 model clutch adjustment. The mechanism is ball and ramp on the 1981 A2. The book is printed to turn the clutch adjuster bolt clockwise till tight and back off. It took a few pops and clutch cover removals for me to realize the adjustment was fully open and allowing the mech to pull through the ball and ramp. Turned counter clockwise and backed off a bit and things were as they should be. Clutch lever input was nice and smooth with clear disengagement.

Another one size doesn't fit all.
Steve