You will find many opinions here, but if you want so profesional advice... REPLACE THE FRONT BEARING. Any time fuel leaks from the bearings the seal is shot, if wd40 leaked passed the front bearing seal with the engine apart it has to be pushing out fuel while running or sucking air in. If you want your engine to run right and not by ruined by an air leak that will make it run very lean when at more than half throttle you have to replace the bearing. While you have the crankshaft out, slide out the sleeve and put fangs on the side ports, put the V shaped cuts on the bottom of the port at the rear of the port that way the air and fuel will go toward the front of the engine and make the air/fuel mixture swirl giving you more power