If the engine is a real Tanaka they are built pretty tough, they last a long time but there is a limit. I have one that has so many miles on it that the chrome on the cylinder is getting thin and starting to peal, it still runs good, but I know that the chrome will get into the piston and ruin it soon. This engine is old enough that I can't seem to find a replacement part for it. If your engine has no compression after you have run it for a while, you might be able to put in some new rings, but if it is one of the aluminum cylinder with a chrome piston it might be a goner. (Just as a note, the manufactures use these engines on all kinds of stuff, if you use a larger one you get the torque but you don't need the speed, so they restrict the exhaust. You can throttle a 2 smoke at both ends. For an experiment just after you get it started cold put your finger with a glove over the exhaust opening and with the throttle wide open, open the tailpipe with your finger, works just like the carb. Thats why when you punch out the opening you get the power increase. Have fun, Dave