yes rossi's are ext tight. plug out turn lots with after run oil. make sure that the copper gasket supplied with engine is fitted. run engine with no more than 5% nitro 18/20%oil defnit caster be patient . great engine with great life when run in properly and cared for with lots of after run when not in use. a3 os plug also works great . dont use to much nitro is the rossi way!!!