'84 Mercury Black Max - semi-stripped spark plug holes. Now what?

[MAtkins]

SN: 6532700

I just got through a complete rebuild.
I've got 2 'loose' spark plugs.
They're snug but I can't crank down on #1 & #6.

I don't know for sure if they're a problem or not.
I fear they'll cause the cylinders to lose compression.

Do I need to worry about them?
I was looking at some spark plug hole repair kits.
Helicoil looked like it might work????

 

[Chris1956]

I like the solid inserts. You need to pull the head, drill to the correct tap size and tap 'em for the insert. Put some epoxy on the inserts and install them.

 

[Dukedog]

TIME-SERT® PROFESSIONAL SPARK PLUG THREAD REPAIR KITS............tha best.

 

[MAtkins]

I still haven't decided on which insert.
What is the size of my spark plug holes? I'm thinking M14 X 1.25"
Is that correct?

Also, this motor has never been started after the rebuild.
When I take the heads off, do I have to buy new head gaskets again?

 

[wired247]

I like the helicoil save a thread repair kit. You really dont have to remove the head to use it. Screw the tap in and it cuts to the next size. Screw the inert in and stake it with hthe supplied swaging tool. Shop vac over the hole for a few seconds and screw the plug in. Ive used quite a few over the years and never had a problem or failure.

http://www.amazon.com/Helicoil-5334-14-Save-A-Thread-Thread-Repair/dp/B0002SRF4O

 

[MAtkins]

Thanks again Wired - that helps a *lot*.
Sav-A-Thread Helicoil is ordered.
My reach is 1/2". Can I cut one of the longer inserts to that or do I need 2 inserts 14MM X 1/2"?

 

[wired247]

PM me your address and I can send you a couple of the medium length ones Ive got a bag full

 

[merc150]

What wired247 said.....Thats the best way to go...Ive used them

 

[dazk14]

Yes, the aforementioned Helicoil kit works great. Load it up with heavy grease to catch chips and clean periodically, The specific insert sizes can be purchased alone (6 pack and up).
If the head hasn't been heated, reuse the head gasket if you choose to pull the head.