Yeah, olds hit it right on the head.
You will see two grub screws, one on top is sticking out towards the edge. Do NOT turn this one.
You want to turn the one on the bottom. It should be recessed in further than the top one. You will need a 2.0mm hex head to turn it.
Here is how to turn:
--- Counter Clockwise (Left) for Earlier Gear Shift
--- Clockwise (Right) for Later Gear Shift
Make sure your engine is off b/f attempting to adjust the screw. You want to make adjustments in 90 degree increments. It doesn't take much to adjust the shift point. Simply give it a 90 degree turn & then drive it to see how you like it. Give it a couple of high speed runs to clear the carb out and let it get used to the shift point. If that is still too early, give it another 90 degree turn.
Just make sure you don't turn the top screw. That one actually should be thread locked from the manufacturer. If you turn it, you will break the lock seal & will need to put some more thread lock on it.
I have heard that you have the shift point dialed in perfect sync w/ the engine's RPM if the tranny shifts and you don't even hear it shift. I don't know how true that is though.
Later.....:mex: