I recently got a used scedu 30 and the starter shaft coupler keeps coming loose from the main shaft rendering it inoperable.When i try to fsten it,it still comes loose.It almost looks as though the main shaft is completely round,no flat area to anchor the starter coupler to.Any suggestions?Has anyone encountered this?Thanks

Try to dremel a new flat spot on the shaft. Also make sure the shaft wasnt stripped round from a spinning set screw. You might need to replace the shaft. But try the dremel first and dont forget locktight on the set screw.

thanks we tried this it worked briefly,i am going to replace the shaft so as not to damage anything.

I had this happen only once, my fix was when tightning the start coupler I rocked the start coupler back and forth lightly while tightning the setscrew, this along with some blue locktite on my ship took care of the problem. Seems that before, I only thought I was seated on the flat portion of the start shaft but I was offset only slightly, rocking seemed to get that setscrew truly seated on the shaft. Sounds like your going down the right road by replacing the shaft if the flat is gone.

Thanks for the replies,we have fixed it.