Just went through a frustrating adventure with stripped Spark Plug threads
in my 1979 Johnson 25.
THREE trips to NAPA to get a Thread Repair Insert to get the right one.
I would like to pass this little tidbit onto my fellow boaters.
GREAT item to keep in your tool box for less than $8.00 for two.
#1. Took cylinder head to a LAWNMOWER shop to get the Heli-Coil thing done.
He was out of inserts. I went to NAPA 3 blocks away to get the insert for him.
(HE called ahead to order the part).....
After I got it home, found it was too short - removed it with a Screw Backer Upper Thingy.
#2. Went BACK to NAPA for another thread insert. The Heli-Coil type with the individual
threads that just thread into the rethreaded spark plug hole......
I didn't like the way it fit into the threads so I took the cylinder head to NAPA for them
to look at it....... and ordered ANOTHER insert
#3. Next day .... went BACK to town, got the insert, put it on a spark plug and it was
a good fit. applied a few drops of HIGH TEMP THREAD LOCKER and the insert went right in and
locked into position quite nicely - very satisfied with overall results.
Edit: Yes, the "heat release point" is 450 to 500 degrees F. It says that on the product label.
so, if your cylinder head is that hot, I am quite sure you will see paint bubbling and turning gray and a
stinky burnt smell at that point. Which means you have far more problems than a loose thread insert
to address.
It is NOT recommended to put any kind of sealant on the Heli-Coil type that has the individual spiral threads
or you will essentially glue your spark plug into the hole !!
This is the item that people should have in their tool box !!! Well worth the advance planning.
I use L77JC4 Champion spark plugs. This item is a MEDIUM size. It comes in small, medium and large.
There is nothing more grand
than to be just simply messing
around in and old boat. POGO-1960
in my 1979 Johnson 25.
THREE trips to NAPA to get a Thread Repair Insert to get the right one.
I would like to pass this little tidbit onto my fellow boaters.
GREAT item to keep in your tool box for less than $8.00 for two.
#1. Took cylinder head to a LAWNMOWER shop to get the Heli-Coil thing done.
He was out of inserts. I went to NAPA 3 blocks away to get the insert for him.
(HE called ahead to order the part).....
After I got it home, found it was too short - removed it with a Screw Backer Upper Thingy.
#2. Went BACK to NAPA for another thread insert. The Heli-Coil type with the individual
threads that just thread into the rethreaded spark plug hole......
I didn't like the way it fit into the threads so I took the cylinder head to NAPA for them
to look at it....... and ordered ANOTHER insert
#3. Next day .... went BACK to town, got the insert, put it on a spark plug and it was
a good fit. applied a few drops of HIGH TEMP THREAD LOCKER and the insert went right in and
locked into position quite nicely - very satisfied with overall results.
Edit: Yes, the "heat release point" is 450 to 500 degrees F. It says that on the product label.
so, if your cylinder head is that hot, I am quite sure you will see paint bubbling and turning gray and a
stinky burnt smell at that point. Which means you have far more problems than a loose thread insert
to address.
It is NOT recommended to put any kind of sealant on the Heli-Coil type that has the individual spiral threads
or you will essentially glue your spark plug into the hole !!
This is the item that people should have in their tool box !!! Well worth the advance planning.
I use L77JC4 Champion spark plugs. This item is a MEDIUM size. It comes in small, medium and large.
There is nothing more grand
than to be just simply messing
around in and old boat. POGO-1960