KZ200A1A Mixture problems (?)

I have a newly revived 1978 KZ200A1A. This bike was my mother's when she rode in the late 70s/early 80s (before I was born). Since about 1982, it basically sat around collecting rust until I took it apart and put it back together.

New tires, chain, sprockets, piston rings, tank sealant, and many hours of labor & learning later, I've been able to ride it around a bit.

This was basically my first mechanical project and I got through it only with some advice from very skilled friends.


On to the point of the post.

It seems like I am not getting the air/fuel mixture correct, or I'm not understanding what's going on. When it starts up, it tends to idle too low. If I adjust the fuel/air screw so that it's idling smoothly, then once it warms up, it idles way too high at around 3000 rpm. If I then adjust the screw so idle speed drops to a healthy 1200 rpm or so, then the next time I ride, idle speeds are too low.

In addition, if I don't bump up the idle speed when it's running low at startup, then the bike stalls while I'm driving if I hold in the clutch while approaching a stop or while sitting at a stop.

After these stalls, the bike is quite difficult to start up again. This is after driving around a bit so the engine is already hot -- it's harder to restart after the stall than it is when the bike starts up cold.

Even more: on one occasion while I was driving at ~55-60mph (almost as fast as the bike will go), there was a loss of power followed by a stall when I pulled off to the side of the road and again, a subsequent difficult time starting. I thought that just possibly there was either too little fuel in the tank (unlikely) or the normal fuel inlet was clogged, so I put the petcock on the reserve setting. I haven't experienced this power loss/stall since, but I've only ridden it once since then. I doubt the reserve setting was a solution, but I don't know that for a fact.

I've been long-winded, but I know it's probably tough to diagnose something like this remotely. I would appreciate any suggestions.

A more general question: should I be worried about heat? This is my first bike and it seems like it gets very hot. A little spritz of water on the bike acts like it the heat fins and muffler are a propane grill on high. How hot is too hot?

A second general question: since this bike only gets up to 65mph or so with the throttle wide open and the wind at your back, is there any danger of me driving at 7000 rpm in 5th gear to and from work?

Thanks for reading