Stripped Tank Threads

[Aidan Smith]

Hello again,

Working with an old tank, would like to keep it original to the motor. However, the internal threads for the gas cap have stripped over time. Is this something I would be able to repair, or should I be looking for a new tank?

 

Thanks,

Aidan

"Shells sink, dreams float. Life's good on our boat."
1931 Johnson A-50
1950 Mercury KF-7
1951 Mercury KG-7
1956 Johnson JW-12R

[George Emmanuel]

Why don’t you tell us what the tank is for and post some pictures of your concern.

George

 

1 user thanked author for this post.

Aidan Smith

[Aidan Smith]

George,

The tank is on an old Johnson, and I would just like to keep the motor completely original, for the parts I have.

I don’t have a picture of the tank currently, but I will get some when I get home from work this evening.

 

Thanks,

Aidan

"Shells sink, dreams float. Life's good on our boat."
1931 Johnson A-50
1950 Mercury KF-7
1951 Mercury KG-7
1956 Johnson JW-12R

[RICHARD A. WHITE]

One can “crush” the neck back down to the appropriate size, with a proper sized threaded rod/arbor so that it fits in the threads to prevent making it too small. Think a band clamp, but a tad stronger.. Knowing the thread size and a friendly machinist that can thread can make the plug, then just figure out how to collapse the neck back down to size… bonus info, if you know what size the threads are you can purchase a cheap Chinesium tap and then make the neck a tad smaller and recut the threads. By you SIG I am guessing that the motor is the 1930 model?

http://www.richardsoutboardtools.com
classicomctools@gmail.com

1 user thanked author for this post.

Aidan Smith

[Aidan Smith]

Richard,

This motor is not listed on the SIG, but it is a 1941 Johnson MD-20, similar to an HD-25. The internal threads of the tank are completely smooth, and I would consider re threading it, but finding a new filler cap may be difficult.

"Shells sink, dreams float. Life's good on our boat."
1931 Johnson A-50
1950 Mercury KF-7
1951 Mercury KG-7
1956 Johnson JW-12R

[RICHARD A. WHITE]

Aidan Smith wrote:

Richard,

This motor is not listed on the SIG, but it is a 1941 Johnson MD-20, similar to an HD-25. The internal threads of the tank are completely smooth, and I would consider re threading it, but finding a new filler cap may be difficult.

Then probably best to find another tank….they are somewhat plentiful….

http://www.richardsoutboardtools.com
classicomctools@gmail.com

[Waunnaboat]

If you are really good with resins and whatnot, there could be something to be said about using the gas cap as a mold and placing it in the gas tank hole with some sort of lubricant so that the gas cap can be removed.  That is just a thought, and I don’t know if it would work.  otherwise, you could probably take the gas cap from some other fuel tank and weld it on, but at that point you might as well be looking for a new tank.  Richard’s suggestions would work a lot better than those two.

"Outboards seem to multiply exponentially..........I find that for every finished project, there are two more waiting to be completed."

[Author]

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