Stripped oil drain thread

[uddmond.]

G'day all. I was changing the lower unit oil on my 2009 Yamaha 90hp today.
Now the oil drain plug won't tighten & the threads are rounded off.
Should I drill & re-tap a new thread & use a larger plug or fit a heli-coil? Any other ideas.
Does anyone know what type the thread is on the drain plug?
Cheers

[rodbolt17]

I use heli coils on customers that strip the thread.
measure the plug thread OD and pitch for the correct size.

[uddmond.]

I use heli coils on customers that strip the thread.
measure the plug thread OD and pitch for the correct size.

Thanks for info rodbolt17. I ended up fitting a Mercury drain plug which is slightly larger at3/8. Thread tapped & good as new Cheers m8.