'85 FLH 80" w/higher compression has been thru 5 starter drives and 3 starters in less than 1000 miles. Will start the bike appx 15 times before mashing the leading edge of the starter drive teeth, continued use will then take out the starter shaft teeth. Have replaced starter, bull gear, starter drive, throwout fork and have installed the shimming washer.

Any thoughts?

My only thought: bike has custom outer primary - might the outter starter drive bearing hole be out of position???? if so, how can that be determined? Any particular measurement to take??

At wits end and running out of time, $$ & patience.

 

What does the ring gear on the clutch basket look like? I would change that out. You have an aftermarket outer primary. That is a potential source of problems too. I don't know how to check the alignment on that, short of pulling the inner and outer and looking at it that way with a shaft stuck in and seeing if it is all centered. Are there different teeth per inch ring gears and/or starter gears? I don't know. It sounds like someone has been in there and seriously swapped stuff around. When in doubt, go back to OEM.

Only 15 starts per set indicates something seriously wrong.

 

My 85 FXWG starter gear went out but not due to grinding. It started to spin freely when I pressed the starter button. I replaced it with an accel from JP. Works fine now.

Sounds like the jack shaft is positioned too close due to the outer primary. There should be a locating pin in the front of the primary to prevent an ill fit between inner and outer covers. Is the pin missing?

Maybe your solenoid isn't pushing the gear out all the way. Try inspecting,cleaning,geasing or replacing it to see if it fixes the grinding.