thread issue for where you screw in the spark plug

[Gotem]

I have an old Johnson 9.9 from 1974. When I replaced the spark plugs last time some of the thread where the spark plug screws into the outboard began to unwind from the spark plug terminal. I am talking about the thread from the outboard unwinding where you screw in the spark plug. Is there an easy way to repair it. The motor still purrs like a kitten.

 

[fordwrench]

Heli-coil

 

[jasper60103]

You can replace the cylinder head or helicoil as suggested. I've had success with save-a-thread.

 

[Pappy]

Go to a NAPA store and get the Sav-A-Thread. Have used this process sucessfully on several occasions. It is easy and secure since the insert is a tap to lock part. Everything necessary to do the job is included with the kit which makes life even more easy!

 

[Charger25]

I've had great success with a kit I got from NAPA. But I pulled the head to keep the metal shavings out of the cylinder. Pretty sure it was 14mm. It came with different length inserts.

 

[Ralph]

Go slow and put grease on the tap to catch any metal shaving from going inside.

 

[rdixiemiller]

Turn the motor over on a workbench with the spark plug hole facing down over the edge of the bench. Turn the flywheel until the piston is at the bottom of its travel. Kind of an awkward way to work, but it let's the tapping shavings fall out of the engine instead of going inside.
I have done this twice over the years, worked for me.

 

[cva34]

You can replace the cylinder head or helicoil as suggested. I've had success with save-a-thread.

Removed head and had great alu.welder weld up hole then drill and tap...cva34