At one point in time I used to open up my starters when they lost there zing and install new brushes { local hardware store} and clean everything in it then spray it with electric terminal cleaner spray. That always fixed it.
These days I just wait for the starters to come up on sale at the big chain hobby stores and buy a new one and keep it on hand. I also go to Harbor Freight and buy the 18 volt battery pack and charger, the two items cost about $15.00. Once this 18 volt starter is wired in I have some serious starting power.
Over in Q&A John Buckner was just showing his new battery pack on one of his starters, instead of 18 volts he went with a nice 24 volt battery pack. Can you say ZING!!!!!!!!!!!!!!!
