Cleaning the Threads of Tank Mounting Screws

[Kim]

Thought this MIGHT be a little over the top, but considering how some of you seem to suffer from the same O.C.D. that I do, figured I'd post this. If it's shown up previously, please forgive.

With the constant (and justified) emphasis on fuel and internal cleanliness, this is something I've been doing for a long time to help insure bits of goop don't face off with my needlevales.

A pretty good length of the mounting threads on tanked engines are constantly bathed in fuel as the engine does it's thing. Especially with older engines or restorations, the open threads can become packed like teeth needing a good flossing. Soaking and brushing will work, but I like to chuck them in a variable speed drill, and run a die down to the head and back, then re-soak them in my fuel tray.

There ALWAYS seems to be a considerable amount of goop deposits left in the die's channels, and I like to think that this MIGHT help avoid one of those moments when an otherwise friendly engine turns in to moody candidate for the parts bin.


This may hit either the limit for "Super-simple-minded-stuff-that-everybody-knows", or "Man!-you're-over-the-top-goofy!", but that's life in the Skunk Works...

[Admin]

I always make sure that the threads are clean on the ends where it enters the crankcase. I let the screws soak for a little bit then hit them with some paper towels and maybe some toothpicks if the crap won't come out of the threads.

[fit90]

Kim,

Be careful not to cut the threads too many times or else they will not hold as well. A thread file may be a gentler solution to the same problem. By the way, this is a great idea that I have never considered.

Thanks,

Bob

[Mudhen]

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[Kim]

Kim,

Be careful not to cut the threads too many times or else they will not hold as well. A thread file may be a gentler solution to the same problem. By the way, this is a great idea that I have never considered.

Thanks,

Bob

Yeah...I don't do it as a matter of regular maintenance, just long-sitters or strays that need some TLC....figured I'd mention it...with some of these, there's a BUNCH of goo that packs the die's channels. I like knowing that stuff is out of there!

[RknRusty]

I hold my tank screws with pliers and assault them with the wire brush on the smaller of my two bench grinders. It does the job pretty well. It makes working on big engines, cars and lawn mowers, a whole lot easier. I would like to get a tap and die set for all of the Cox sizes.

[dckrsn]

Not unlike Kim's O.C.D., I always chase the crancase threads(2-56 bottoming tap) after a good soak
or ultra-sonic cleaning w/Hoppe's #9 solvent. Then back in the solvent, and blown out
with compressed air. This a must if you are using aftermarket screws that are 3/4"(5cc tank)
or 1"(8cc tank). The old Cox screws are just a tad shorter, but will bottom out in really old, hardened
castor oil, and threading the full length of the hole will accomodate the the aftermarket screws.
Before I started this sacred ritual, screws would bottom out making me think the backplate was tight
and leave me with a leaking engine.
Also the same goes for the prop screw threads(5-40) in the crank.
Oh, and I love doing this.
Bob

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