[DonVincenzo]

Ok so I stripped the lower drain, not the screw, for my 2004 Yamaha 90hp 4 stroke. I have looked at heli coil and time sert and I am not sure which one to use. does anyone have any expirence with either of these and any spicifics would be greatly appreciated. The outboard is used in salt water only.

thanks in advance

Vince

[rodbolt]

use the 8mm helicoil and shorten the heli coil insert by 4 threads.
the standard heli coil is to long and must be shortened.
I get several a year that do it yourselfers strip.

[DonVincenzo]

Thanks for the quick reply. Have you seen any instances where the heli coil fails in this application.

Thanks

Vince

[rodbolt]

if installed properly, no failures.

[DonVincenzo]

Have you used the fine thread or the coarse thread

[rodbolt]

best I remember its 8mmX1mm but use a thread pitch guage on the plug to make sure.