Any gauge will work. Like I said if you can get a gauge with the threads pretty close to the length of the spark plug that's optimal. But if not your reading won't be that far off.
If you can warm the engine up then do it.
With a compression gauge.
-Unscrew spark plug, screw in comp. gauge. Try for gauge with threads about same length as spark plug if possible.
-hold throttle wide open.
-kick.
-kick.
- a few more kicks. One last one and make sure gauge doesn't move. And one for good luck after.
-maintain the open throttle position during the 3 previous steps.
- read gauge.
-report back and let everyone know what you have as a reading.
Hmm, well what if this thing leans out your bike and it explodes? Or goes dumb rich and explodes? Or just all around explodes directly related to a carb issue?