From the look of it, the piston and sleeve seems to roll too lose. After installing the glow plug, I tried to roll the flywheel with my finger, and there isn't much resistance. My old .12 CV seems to have more compression when I compared it. The Sirio is still new...

Will the sand paper method still work? If I take away the scratch, won't I make the piston and sleeve losen up even more? Sorry if I asking dumb questions.

I will still check for air leaks in the carb before spending $100 on new piston and sleeve.