I bought a 2000 kx125, the person selling it started it with a few kicks when i bought it... Then when I got it home I could only start it buy push starting it... (I live 3000 feet higher in elevation than the place i bought it from) I rode it pretty hard for about an hour, rested and took it out again for another hour and it seemed to work great... I mixed the pre mix @ 32:1 using pump gas... I was having a blast and then I crashed... The bike was running on it's side for a few seconds so I hit the kill switch... I couldn't get it to start again kicking, and even when pushing it... I figured i fouled a plug so I put a brand new plug in and it will not start... I checked the compression and i only got 35 psi... It was real hot out when i was riding... Did I blow the head gasket? (no bubbles in the radiatior when kicking it over with the cap off) Maybe the compression gauge is wrong... I made sure I torked down on compression checker adaptor pretty well until the grommet was squished but not squashed... I did this twice and got a 35psi reading... How could it be running and all i did was crash and then have only 35psi... It's not seized or anything... I don't get it... Was it the pump gas? The heat, and elevation?