I am in the process of rebuilding my 12A and want to replace the rotor bearings, as I want this motor to last a while. Wanted to know if it is possible to remove and install new bearings without the specific tool, if not I will buy the suitable tool. Also is there a way to tell the difference between front and rear rotor, got distracted during tear down and forget to label them.

 

their are letters stamp on the face of the rotors

 

buy the correct tool they are relatively cheap. they are brass bearing drivers and they work well. as far as front and rear rotors, you can identify them there will either be an F for front and an R for rear stamped into the combustion chamber on each rotor.

 

if you want to buy the factory ones the part # is 49-0813240 .. go all out a get the main bearing puller & installer and that# is 49-0813235 it for the stationary bearing.......call equipment solutions...(800)824-9655

 

I've always been of the school that says replace the bearings only if they are out of spec or require replacement. I've seen way too many improperly seated bearings spin and take out a rotor, housing, apex seals, and ruin an E-shaft. Plus you will effectively double, if not triple your break-in period with new bearings, as the only way to cure a new bearing is through multiple heat cycles.

Barring some sort of heavy abuse, improper oiling, or other freak accident bearings last quite a while. Not to mention if you increase the oil pressure by modding the stock regulator or using a 3rd gen, your bearings will live a long and happy life.