Stern dolly - centre plug missing, help appreciated

[Capnbob]

For reasons I cannot fathom the plug which should be fitted to the top of the stern dolly (see pic0) has gone missing. I'm wondering if it's just a plug (seems unlikely) or more likely that it has some function,like air inlet valve to the diesel tank below.

 

Boat is a 2003 Liverpool Boats 58' semi-trad.

 

Would be very grateful for advice on:

what is it?

how worried should I be that it's missing?

where do I get a replacement?

 

Many thanks...

[Alan de Enfield]

REPLACE IT QUICKLY

 

That is the vent for your diesel tank and serves two purpose, to vent the tank and stop water getting into the tank. Without it you will be getting rain into your tank and will have fuel problems if not sorted soon.

It should have 'anti-flash' gauze in it to stop sparks igniting the fuel,

 

 

 

 

You are invalidating tour BSS by not having one.

 

Marine Grade 316 Stainless Steel Gas Fuel Tank Vent Through Hull Boat Yacht O7E1 4894847689148 | eBay

Edited August 9, 2021 by Alan de Enfield

[Tony Brooks]

and until you get one, pop an inverted food can over the dolly.

[Capnbob]

Thought so. Thanks everyone.

[Tracy D'arth]

5 minutes ago, Capnbob said:

Thought so. Thanks everyone.

Has it been pinched my someone trying to steal your fuel? Don't get water into your fuel, long term problems will ensue.

[David Mack]

Those breather vents are available with 1/2" and 3/4" bsp threads, so measure your dolly before ordering. Note that for 1/2" bsp the hole will be approx 3/4" diameter and 3/4" bsp is about 1" diameter (the nominal sizes relate to the pipe inside diameter, and these are external threads).

[ditchcrawler]

1 hour ago, Tracy D'arth said:

Has it been pinched my someone trying to steal your fuel? Don't get water into your fuel, long term problems will ensue.

Negates having to bust the padlock off the filler cap.

[Capnbob]

1 hour ago, Tracy D'arth said:

Has it been pinched my someone trying to steal your fuel?

Interesting question. Not theft, because the filler cap isn't locked. It just popped off when knocked by a rope, which clearly wouldn't happen if it was fitted securely. Our best bet is that the marina where we refuelled an hour previously released it to bleed the air out when filling, and then failed to replace it correctly. Nothing else makes sense.

[ditchcrawler]

1 minute ago, Capnbob said:

  Our best bet is that the marina where we refuelled an hour previously released it to bleed the air out when filling, and then failed to replace it correctly. Nothing else makes sense.

Shouldn't be necessary as its a ½" vent

[David Mack]

6 minutes ago, Capnbob said:

It just popped off when knocked by a rope,

Well it hasn't broken off leaving the threaded part behind, so it must have been unscrewed, even if it was then left loose in the top of the dolly.

[Tracy D'arth]

7 minutes ago, Capnbob said:

Interesting question. Not theft, because the filler cap isn't locked. It just popped off when knocked by a rope, which clearly wouldn't happen if it was fitted securely. Our best bet is that the marina where we refuelled an hour previously released it to bleed the air out when filling, and then failed to replace it correctly. Nothing else makes sense.

Crazy if that is the case, no need to remove it as it is a vent in itself.  I wouldn't fuel there again.

[Capnbob]

15 minutes ago, David Mack said:

Well it hasn't broken off leaving the threaded part behind, so it must have been unscrewed, even if it was then left loose in the top of the dolly.

Yup. Not that anyone would admit it, but I can't come up with any other explanation.

[Tony Brooks]

Unless it was an attempted theft that got disturbed before they got the breather off.

[robtheplod]

I never knew about this - I've often wondered why the two posts are different at the back so I've learnt something today, thanks!  I can't recall seeing any holes in the top of the post so I'll have a good butchers when next on the boat!

 

When i google it i get lots of articles about Dolly Parton being angry!

Edited August 9, 2021 by robtheplod

[Capnbob]

To complete the story for anyone who turns this thread up on a search, I did eventually track down the right item. It's a 1/2" BSP fuel tank vent, like this:

 

https://shop.chastheboat.co.uk/products/fuel-tank-vent-1-2-bsp-male-brass?keyword=Fuel Tank Vent

 

 

Edited September 6, 2021 by Capnbob

[TheBiscuits]

Thanks for coming back and completing the tale.  It's much appreciated by those who freely offer advice on here.

 

Many posters don't bother.