Well, I know that the case is not cracked beacuse Ive taked the engne apart and put it back together. The engine is perfectly ok internally, but i have not fiddled with taking the carb off. The engine is a gs-21 pullstart engine. So I am going to take the carb off rihgt now and see if there is anything wrong. Does the type of carb(if i need a new one) matter any good ones to use in my engine? should i get a new cylinder head or will performance still be the same? Should I just go with a new engine all together? Is the Os .21 rz a good choice(dont worry, ive learned from my mistake)? Thanks for your help