Fuel Fill Help!

[Uncle Joe]

Guys.....I have spent the last few weekends replacing my aux fuel tank on my '82 Offshore. Soup to nuts.....fill hose...tank...sending unit....supply line to the engine....selector valve...the works. All is working fine....except the PO seems to have lost the gas cap and used one that doesn't fit properly. Now that I plan on using the tank I need the right one.....

Does anyone know where I can get a cap that fits the original Grady fill port? The threads are 1.75 inches OD.....I have found 1.25 and 1.5 in but no 1.75. I have also bought 2 different fill ports and the top flange on each are too small....only 2 of 3 screws get a bite and I hate that.

Thanks all.

Frustrated in NY.

 

[Halfhitch]

Hey, Unc, did you check this one out?
https://www.ebay.com/itm/313075306725?hash=item48e4be10e5:g:2I0AAOSwpWJetBLk

 

[Uncle Joe]

Hey, Unc, did you check this one out?
https://www.ebay.com/itm/313075306725?hash=item48e4be10e5:g:2I0AAOSwpWJetBLk

LOL....I did Halfhitch.....aside from being about 5x the price it should be, I am pretty sure it won't fit my old Offshore. The escutcheon is considerable larger than anything else I have found.

 

[glacierbaze]

Holy cow! I’m going to put a bigger chain on mine, before the meth heads find out how much a Grady White gas cap is worth. Just from memory, the cap on my water tank fill seems to be the same size and style as the fuel fill. Not sure if it is marked water or plain, but that could be an option, if yours is the same.
My water fill is pretty much out of sight, on the front of the passenger seat pedestal, so I could go generic on that if I had to.

 

[DennisG01]

The deck fill plate (and your cleats) are made from a very special aluminum alloy called Marinium. It stopped being used because it was expensive to produce. However, Perko acquired it a little ways back and started making items out of it. I don't know if you'll find that cap, anymore, but I'd reach out Perko as a start.

In lieu of that, just get a small piece of starboard and mount that to the deck, then mount a new deck fill to the starboard.

 

[seasick]

If you know the fill hose ID (usually 1.5 in and whether the fill is a combo (venting) or not model, I would think you can find a replacement in the Perko catalog

https://www.perko.com/legacy_product_listing/15/page/1/

There are larger fills also by other manufacturers but I think they are used primarily for diesel

 

[Uncle Joe]

Holy cow! I’m going to put a bigger chain on mine, before the meth heads find out how much a Grady White gas cap is worth. Just from memory, the cap on my water tank fill seems to be the same size and style as the fuel fill. Not sure if it is marked water or plain, but that could be an option, if yours is the same.
My water fill is pretty much out of sight, on the front of the passenger seat pedestal, so I could go generic on that if I had to.

That probably would work Glacierbaze but my model did not have a fresh water tank. I would gladly go generic if I could find the right size.....don't really care what it looks like as long as I don't get any water in the tank.

 

[Uncle Joe]

If you know the fill hose ID (usually 1.5 in and whether the fill is a combo (venting) or not model, I would think you can find a replacement in the Perko catalog

https://www.perko.com/legacy_product_listing/15/page/1/

There are larger fills also by other manufacturers but I think they are used primarily for diesel

Tried Perko Seasick....the largest I found is 1.5 in threads.
I do know the hose size is 1.5 in as I just finished replacing it and everything else associated with the tank.

 

[seasick]

I am not sure what you are supposed to measure to get the correct fuel cap. For pipe, measurements would be ID and not OD. Same goes for pipe plugs and caps. But for gas caps?? hmmmmm
I assume you looked at something like this

Seachoice SS Replacement Gas Cap For Deck Fill 32251, 32261, 32271 or 32281 32551 | Zoro

Order Seachoice SS Replacement Gas Cap For Deck Fill 32251, 32261, 32271 or 32281, 32551 at Zoro.com. Great prices & free shipping on orders over $50 when you sign in or sign up for an account.

www.zoro.com

 

[SkunkBoat]

heheh...you could have replaced the whole thing by now ...I got caught in that loop too on my '84 V20. tried 3 wrong ones and then replaced the whole thing

 

[seasick]

heheh...you could have replaced the whole thing by now ...I got caught in that loop too on my '84 V20. tried 3 wrong ones and then replaced the whole thing

Makes sense but I would have done the same thing, look for a replacement cap. You would think that would be simple.

 

[Uncle Joe]

Makes sense but I would have done the same thing, look for a replacement cap. You would think that would be simple.

I have tried 3 different caps and 2 different fill plates.....the threads on the caps range from 1.25 to 1.5 in...I need 1.75 and the top escutcheons on the new fill plates are all too small....I may have to try the starboard thing Dennis mentions. That is the same thing I had to do when I replaced my flush mount rod holders.
Problem is that in 1982 Grady was using bigger and better than standard.