Not enough compression?
 

What is the minimum amount of compression needed for the 150cc? I bought a tester the other day and checked mine cause I still haven't figured out why it wont run and it is pretty low but it seems like it should still be enough to fire, maybe I'm wrong.

The reading I got was 105psi. It's the rings or cyl wall cause the oil trick bumped it up to over 150psi.

Would that low of a reading cause it to suddenly stop running? Because that's pretty much what happened. I never seen a gradual decline in power. It just quit.

IMO you have enough compression for it to run @ 105psi.I got plenty with a lot less running & smoking!! If my engine just up and quit I'd be looking for a disconnected/broken wire or blown fuse.Do you check for spark?If no spark- I would check all my grounding wires first- put a jumper ground straight to the coil ground terminal,I'd make sure the electrical system is grounded to the chassis & motor via another temporary jumper. If you have spark then is going to be fuel related-carb/petcock/tank.