I have a ss125 I just did a top end overall. I've had the bile for about 5 years. The bike had gotten low on compression and starting to smoke so rebuilt it. Bored 10 over, new pistons, rings. Back together it's only run a couple minutes at a time before it dies. Squirting oil in the cylinder helps it crank. Compression is even on both cylinders at about 90 psi. I have done all the obvious. Something I'm missing, not sure.