An engine starter motor is not designed to run for more than 30 seconds (even that may be to long), will overheat and cause the feild windings to fail,or through the solder out of the armature comutator, best bet is to have starter tested AT A REPUTABLE SHOP, not by some kid making 10 bucks an hour. David RV6A Rotary

 

when I had my O320 starter rebuilt last time (actually from a 280Z) I figured I'd try one of the discount shops, figuring that they do high volume, std stuff cheaper.  well, I was shocked when they stupidly let me go out back.  their "shop" actually had a dirt floor with greasy racks of used starters, for parts I guess, and tools from harbor freight.  I discovered I could buy a new one from an automotive electric store for $116 and peace of mind.   kevin