1 and 3/4 inch deck fill cap

Does anyone know where to find a 1 3/4 inch deck fill cap replacement? I kicked mine overboard during a pump out and am finding that these are rather rare. Normal sizes are 1 1/2 or 2 inch and won't fit. I'm finding Marine Trader seemed to avoid standard sizes whenever possible. Any help will be appreciated.

Awhile back "the head mistress" posted a link to a company that sold many sizes and how to measure them.

Anyone have that link or thread handy?

My other computer with those links died last week.

For thge OP...you can search her posts and see what you get...tedious but I think your answer is there.

Maybe HOPCAR can help...shoot him a PM to see what he has cataloged.

Greetings,
Welcome aboard.

See here:

Size Help - TANK LOCK

You might be running into a thread problem. There is some taiwanese supplier who seems to find their way onto many boats, and they use a non-standard thread pitch. Many deck fittings are 1-1/2" pipe size with an 11.5 TPI thread cut. This matches standard pipe threads for that size pipe, but it's a straight cut not a tapered cut. The mystery supplier instead uses 14 TPI. This is what I have on my boat, and it was a real bitch to figure it out so I could make a pumpout fitting with a banjo coupling. Nobody makes an off the shelf fitting for it.

One suggestion would be to try MMI Marine Replacement Parts for Taiwan Boats | MMIMarine.com They have quite a few of the asian parts used in many boats. Check the web site, but you will likely need to call them. They are very helpful.

Deck fills are a dagger aimed at the heart of the boat , the fuel, fresh water or poop dump.

Our remedy is to scrap the fuel deck fill and install a 6 or 8 inch deck plate .

The fuel fill hose has a pipe nipple with a pipe cap , and is only exposed when the plate is lifted.

A bad seal or lost O ring or gasket can cause a major headache with all of these openings.

Even a brand new deck fitting from a hood US mfg does not solve the long term problems,

FF said:

Deck fills are a dagger aimed at the heart of the boat , the fuel, fresh water or poop dump.

Our remedy is to scrap the fuel deck fill and install a 6 or 8 inch deck plate .

The fuel fill hose has a pipe nipple with a pipe cap , and is only exposed when the plate is lifted.

A bad seal or lost O ring or gasket can cause a major headache with all of these openings.

Even a brand new deck fitting from a hood US mfg does not solve the long term problems,

Click to expand...

Great tip Fred. Great solution not a yacht solution. Sounds easy to fabricate too.

"Great solution not a yacht solution."

There are large deck plates made in chromed bronze or SS for the white boat folks.

Plastic works for the $$$$ challenged.