Force 125 LU drain plug replacement.

[notop]

I have an '86 Force 125. The allen-head drain plug is stuck -- and the hex-socket part of it is stripped. I took the LU to a fabricator shop where we tried to weld on a bolt, but there wasn't enough meat on the allen screw to get a decent weld and so the welded bolt just broke away from the allen screw when we tried to loosen them. I have soaked the thing for days in penetrating oil, have tried heat and hammer-taps, and no I have just drilled to put a screw extractor in. Not having much luck... I am turning so hard it I feel like the screw extracto is about to bust. So now I'm thinking ?'m goin to end up drilling the screw completely out and re-tapping it to a larger size. Can anyone tell me how thick that housing is? Will a 1/4-20 bolt have enough threads, or should I go 1/4-24 or 1/4-28 ? Suggestions for anything else?

Thanks.

 

[wickware]

Re: Force 125 LU drain plug replacement.

Possibly you can drill in steps to get to the L/U threads w/o damaging them and pic plug's threads out before over-sizing. With Luck! The plug?s threads will come out with an extractor once you get close. Once you get close, use a small punch to punch the threads toward the center to try and free them from the outer dia. Good luck! jow

 

[Frank Acampora]

Re: Force 125 LU drain plug replacement.

The drain plug is already 5/16. Drill it out with slow speed and a cobalt steel bit and tap the hole to 1/8 NPT. Then go to the hardware store and buy a 1/8 pipe plug. DO NOT tap too deeply. NPT taps are tapered so they will seal. Use the plug as a guide as to how deep to tap. Do it in stages until the plug fits without sticking out too far. NPT plugs come in steel, brass, and stainless. They also come in square head, hex head and allen head.

If the existing hole is too large to adequately tap 1/8 NPT, then use 1/4 NPT. However, if you are adequately careful, 1/8 should do. The stainless slotted plug on top of the head is 1/8 NPT. (Unless you have a temp gauge sender there)

If your local store does not have what you need try Graingers or McMaster-Carr.

If your plug is located on the bullet, just ahead of the skeg, there is about 1/2 inch of aluminum there.

 

[notop]

Re: Force 125 LU drain plug replacement.

Okay, thanks guys.
I've stepped my way through the drilling, and managed to remove most of the stainless remnants of the old plug with a small chisel. There was still some thread left, but not enough for my comfort, so today I bought a 1/8" tap and an 11/32" drill, and I plan to start tapping tonight. Just wondering though: would you recommend teflon tape or never-seize compound on the plug before it goes in? I think teflon tape has a tendency to shred when you take the plug out and I fear that pieces of it might make their way into the LU. Not sure if my concern is legit, though. I use a product called Coppa-slip on almost all my car parts (especially lug nuts!) and I'm thinking to give that a go with a brass plug. The motor is never in salt water for more than about 8 hours at a time, so I don't think corrosion of the brass will be a problem.
Thoughts, anyone?

 

[Frank Acampora]

Re: Force 125 LU drain plug replacement.

Copper and brass is an absolute no-no with aluminum. It forms a very efficient galvanic battery--especially in the presence of salt.
The copper in brass disassociates and both brass and aluminum will corrode--that's why old props were BRONZE--naval bronze.
Spring for the extra couple of bucks and get the stainless plug. --Worst case scenario: Order a stainless slotted head plug from Mercury if still available. Teflon tape is OK as even if it does get into the lower unit it will not harm anything. Nickel based anti-seize will work too.

 

[notop]

Re: Force 125 LU drain plug replacement.

Okay, thanks for the warning about the brass/aluminium. I can't find any stainless plugs at the local hardware stores, so I'll order a few through a specialty fastener supply company I know. Probably take a few days, and I think I'll hold off the tapping until I get them in my hand so I don't tap it too shallow or too deep. 'Til then, cheers.

 

[jason32038]

Re: Force 125 LU drain plug replacement.

I dont know if this post is too late but...I hammered a torx bit into my stripped LU drain plug and twisted it out with a crescent wrench.