I know this is a forum for 4 wheeled vehicles, but once again I have a question about a motorcycle, lots of the basics are the same. i have a 1970's harley rapido 125 2 stroke, when i got it, it ran, but had no power under load, so i cleaned the carb all up, and put it back together, same result. it will rev to the moon in neutral, or with the clutch pulled in, but try getting it to move, and it just dies. i ran alongside it, reved it, nothing will get it to move. lift up the back end, and it will spin the tire! anyone have any ideas, or have their wheeler do this, i need some help!
thanks

 

First thing to do is a real compression test. Do the test and post the numbers.

 

Ill have to borrow one, then ill post the numbers,,,,, thanks for the help
do you think its a carb problem, or a motor problem
it was rebuilt before i bought it .30 over, new piston and rings, think it might be this?

 

I can't say right now. Could be many things.
One thing is for sure; it will have no power if you are low on compression. That is why it's the first thing I check.