the heat of the motor run after run weakens the magnets over time... zapping the magnets on a good zapper, can bring thm back to new or in some cases better then new...
the key is to find a good zapper.. they uaually run a 500 bucks or more.. thats why its good to find one, and pay a few bucks to have it done... i have been using a good one.. i notice a huge difference.. most magnet zappers ccome with a meter, to read the magnets power... you can do a before aand after to see the results... it does help alot on old tired motors
you cant get a magnet to hold more then its rated for.. but on some new motors, the magnets are not as good as they are rated.. this is where it helps when there new.. most motor builders, will zap a motor when they are new.. this assure maximum magnet strength...
HERE IS MY TRADER FEEDBACK ON HOBBYTALK. http://www.hobbytalk.com/bbs1/itrader.php?u=8257