Piston ring

Ya've two because they're supposed to "overlap" so the ring gap is in two locations reducing blow by (four strokes often have a third as an oil scraper)...

Ya could try it I suppose - but yer compression is gonna be pretty bad

22.5cc? Do you have an ol' Bike Bug or is it a weedwacker er sumfin'?

My buddy just ran for 2 days last week on 1 ring, although he did lose compression it wasnt that bad but he got quite alot of piston slap causing his bike to sound like he was riding a canary lmao!