Over tighten main sump drain bolt!

Took it to dealer and they fitted heli coil and all was ok until I changed the oil again and now there is a very slow leak from the bolt. Can anyone suggest a fix for this? Too scared to tighten any more! Thanks

Use a new washer and tighten to spec. If strips you can always remove the helicoil and tap the nut out to the next larger size. I'm guessing that would be stronger than a helicoil. Maybe someone else has better advice?


I too did the same thing including installing a helicoil. My slow drip went away when I went to a Ty Davis magnetic drain plug which also included a new washer. No more problems.

Good Luck,


if you take out the helicoil make sure to put in a timecert.


Since Yamaha has created a porthole in the side of the threaded boss in an attempt to insure full oil drainage the sump thread is very easy to strip.

It is also very easy to heli-coil or timesert it crooked as well.

If the sealing face of the washer is not flat against the fastener surface it will drool.

Good luck with this one...

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