SPARK PLUG CROSS THREAD

[yap-yap]

THREAD ON SPARK PLUG WILL NOT HOLD BECAUSE OF CROSS THREADING,
WILL JBWELD APPLIED TO TO WALLS HOLD PLUG ?

 

[racerone]

Install a heli-coil.

 

[Scott Danforth]

THREAD ON SPARK PLUG WILL NOT HOLD BECAUSE OF CROSS THREADING,
WILL JBWELD APPLIED TO TO WALLS HOLD PLUG ?

No

The following will hold:

Install a heli-coil.

 

[racerone]

Loosen sparkplugs with a wrench.----Remove by hand.-----Install sparkplugs by hand and snug up with a wrench.-----If you are removing / cleaning sparkplugs each trip , then repair / tune-up the motor !

 

[QBhoy]

Needs heli coiled…and properly done too. Or ideally a replacement hood used cylinder head instead

 

[racerone]

Many Mercury motors do not use a cylinder head.

 

[Chris1956]

A heli-coil is one option. There are solid threaded inserts as well. Both require the spark plug hole be drilled oversize and threaded for either the heli-coil or the solid insert.

Hopefully you have a newer Merc, where the head comes off.

 

[Lou C]

Might want to take it to machine shop & let a pro do it…

 

[merc850]

I have used the steel insert and it went well but you have to use Loctite to hold it in. It seemed to be better than a Helicoil as it gives a complete steel plug hole.

 

[flyingscott]

I have used the steel insert and it went well but you have to use Loctite to hold it in. It seemed to be better than a Helicoil as it gives a complete steel plug hole.

how does a Heli coil not?

 

[TrebyM1]

A helicoil is by far the best. The more you tighten, the better the grip...... providing you have used the correct size drill for the hole. The only likely problems are metal "shavings" in the cylinder head and when removing the plug for replacement, the helicoil may come out with it.
Good luck

 

[racerone]

I have a kit to install sparkplug heli-coils.-------It has a leading thread that goes into what is left of the original thread.-----Lines it up and then cuts the thread for the heli-coil.------No drilling required !!

 

[TrebyM1]

Not actually used that particular tool but checking google, it seems a good way to go. I don't think JPWeld or any other adhesive will be necessary.