One thing I see is, some have different phrases, words, to explain different things. It sometimes gets confusing, for me anyway. So what's new?
These are the terms I use;
when I 1st hit the throttle, and the engine is being held at some RPM, and that RPM is more than the axle is turning, divided by the gear ratio, I call that stall. Meaning the clutch is holding the engine at some RPM, and the axle rpm is less than the engine RPM divided by the gear ratio. To me, lockup is when the engine RPM, divided by the ratio, is the same as the axle. If you have a 4/1 gear ratio, when the engine is turning 4000 RPM, if there is lockup, the axle would be turning 1000 RPM. If you have the clutch adjusted to where it is holding the engine at 3600 RPM, it won't be locked up until the axle is turning 900 RPM. As you pick up speed those numbers will increase. As the axle rpm increases, the engine RPM will increase, but you will not necessarily be at lockup. The Delta, (the rpm difference between the engine and the axle) should get smaller and smaller as the kart goes faster and faster. You should never see, (feel) a decrease in rpm as you accelerate. Sometimes, if things are not right, you might see a drop in rpm, feel the clutch lockup, and then you accelerate. This should not happen. If it does, it could be caused by the engine going a little lean, or the clutch getting a little too hot. When things are right, you very seldom feel the point where the clutch locks up. It should be a very smooth transition from where the clutch shoes are slipping to where they are locked up. (Engine spinning at the same rpm as the clutch drum) Of course there is always a little slip, but it's small.
I hope that makes sense. lolo