compression?

[scootnoob92]

I've got a 150cc jmstar and I cleaned the carb and did a compression test, but it's reading 125 on my compression so I put a little oil in the cylinder and compression jumped to 150. So I think it may be the rings.. And also when I start it up it'll run fine for about 30 seconds then the motor revs high without me giving any throttle. any suggestions to what it could be?

[qwertydude]

Possible air leak in the intake somewhere. Also have the valves been adjusted?

[techie610]

If putting oil in the Cylinder raises compression, then you probably have a scarred cylinder, or wore rings.

[jct842]

How many miles have you put on it? If it is new or low mileage the rings may not be seated. If there is a lot of miles on it you can make plans for new rings or top end.