Stripped Port Side Block Plug hole threads

[bishop1976]

The threads in teh hole are stripped according to the boat guy. Says he doesnt have the tap to straighten out the threads. Any ideas?

 

[ken_23434]

Re: Stripped Port Side Block Plug hole threads

Is this a plug to drain the block? ie it goes to a water passage?

If so, just get a "Heli-Coil" kit. It will have a tap, some lock-tite and a spring looking thing. The tap will cut the threads for the ouside of the spring looking thing to screw into (held with the lock-tite) and the inside of the heli-coil has threads to match the original hole. When done, you basically restored the original hole back to "normal" with the correct pitch threads.

They also sell heli-coil kits to fix spark plug holes, but I would strongly consider pulling the head before doing that one. As, any shavings would drop into the cylinder during the tap routine.

 

[ken_23434]

Re: Stripped Port Side Block Plug hole threads

One more thing, find another mechanic... stripped hole repair is pretty basic for a mechanic.

 

[Howard Sterndrive]

Re: Stripped Port Side Block Plug hole threads

those drain holes are NPT (tapered) threads. Just clean them up with an NPT tap.
If the hole is worn out, the tapered tap will still clean it up fine, just need some permatex or teflon tape on the drain tap fitting or plug tighten and seal afterwards.

I totally agree that your mechanic is lame. What mechanic doesn't own a set of taps and dies?

 

[Alumarine]

Re: Stripped Port Side Block Plug hole threads

If it can't be fixed with the correct tap you could always go up a size if you have the room.

I had one of my 1/8" NPT drain holes strip out due to corrosion.

I tapped it out to 1/4" NPT and put a 1/4 x 1/8 brass bushing in it so I could continue to use the 1/8" plug without fear of losing the cast threads again.

 

[Bondo]

Re: Stripped Port Side Block Plug hole threads

The threads in teh hole are stripped according to the boat guy. Says he doesnt have the tap to straighten out the threads. Any ideas?

Ayuh,... That's a novel Idea,.... A Mechanic Without Tools.....
It's maybe a $10. tap,... maybe 1/2 that,... for Quality at that...for a Tool that's used Alot...

Your Problem with the boat is reasonably Minor,....
Either You've gotta start buyin',+ turnin' Wrenches, or hire a guy With Tools...

 

[bishop1976]

Re: Stripped Port Side Block Plug hole threads

lol...I think i don't have the tap meant "I don't want to mess with it". They guy is a great Mercury mechanic.He won't touch anything he doesn't feel comfortable with. I don't think he felt comfortable with opening up that can of worms.

I'll try to run a tap in it of the same size as the plug. See what happens.

 

[bishop1976]

Re: Stripped Port Side Block Plug hole threads

One last question. When installed are the plugs supposed to be flush with the block?

 

[Bondo]

Re: Stripped Port Side Block Plug hole threads

When installed are the plugs supposed to be flush with the block?

Ayuh,... If it snugs up,+ Don't leak,.. It's Good....
The plugs are Tapered,..
If you get to the end of the threads,..
It's probably time to start thinking about Doing something about it....