Make sure your idle speed is 1000 rpm or better. I had the same problem when I tried to get my scoot to that "loping" idle like a Hurley. A low idle speed also causes overheating and poor oil distribution.

Mike without seeing your VOM it's hard to know,but I think you're on the right track. Try putting the clamp over the plug wire and see what you get. If the reading seems extremely high divide the reading by four(some ignition systems fire on every stroke,not just the power stroke).You can tell by the sound if you are within range(bike won't stay running much below 750rpm and redline is around 6500 rpm).

Adjusting idle is fairly simple,just locate the throttle cable connection at the carb and look for a screw on a linkage that moves as you twist the throttle. The point of the screw rests against a stop on the linkage when the throttle is at rest. Adjust the screw in(moving the plate away from the stop) to speed up the idle.Move the screw out to slow down the idle. Just remember the starting point and make small adjustments. It's best to have the scooter warmed up to operating temps before adjusting.

If I've missed something in the process others will be along to square you up!

Mike I just had another thought.....some of the VOM's with a tach were meant to read rpm of an electric motor. Not sure if those will work on our scoots. Just sayin!

Good luck and let us know if it works!

My bike used to have a bit of a hesitation just off iidle, and I rode a used bike before I bought mine that rode the same.  After I rejetted the carb and did the spacer mod the bike runs great.  My bike was just too lean at the idle to 1/4 throttle settings and the engine did not run smoothly.  I ended up with a 150 main, 50 pilot and 2 washers on the needle (start with 3 first).