Ok my OS 15 engine has an air leak!! Me and my dad investigated it, took apart the entire engine. We didn't think any of the parts appeared to be so worn out they can cause an air leak, since the engine is fairly new too. We did however find that there was a leak from the bearing thats near the flywheel, if you know what i mean. The bearing that holds the crankshaft on the end of the engine thats connected to the fly wheel. So we put some grease on it to stop the leak, and the engine started fine. Halfway through testing time, the engine seemed to run erraticly so i put my finger on the exhaust to stop it. BUT the engine just kept running!! So i pulled off the gas line and it died. My question is: is it the bearing that needs to be replaced? Or is there something else leaking?? The engine has gone out of control before, screaming like #@$% and i had to run over to it and stop it. Is it because i used to have a 1 speed tranny and i keep gunning the engine? I need help!