speedtrash

i just cant seem to get my engine to fire. the guy i bought my baja 5b from said it was a cy that went to o neills to become a 30.5 from a 29. ive talked to him since buying so im not ready to give up on the engine, he says its a good one. now i am experienced in rebuilding nitro engines so i pulled the head when i noticed it looked like dirt or crud atop the piston(turned out being the texture on it). when trying to reinstall the head i didnt realize it had a dimple te ring was supposed to sit on so i thought i had an issue. in resolving the issue i pulled th ering off and tightened it up to where it is tight against the piston. im assuming at this moment that might be my issue because when i took the head off the ring opened up as to put pressure on the cylinder walls.

other than that i have spark on my plug(not a new plug).

now if it is my ring would i be alright to just open it up a little to where it was before? or just buy another?