In changing my lower unit oil, I stripped the female threads in the aluminum case on my Yamaha 90 HP 1988 outboard. Should I just go to a machine shop or is there a over the counter remedy?
its called a heli-coil. but you have to shorten about 3 coils from the standard insert and make sure you retrieve the coil drive tang or it will fall into the case.
measure the drain plug thread for the correct size insert kit.
