Saving Old Seagulls

Liam, you 100% correct!
It should be a 7/16 x 18 BSF.

I will make the change up the top.

Thanks for pointing it out.

Took my boat and Silver Seagull out for a run today (first day off in 6 months) only to find it was not pumping water very well. Pulled the water intake pipe off to find the brass fitting that goes into the block half blocked with hard rust. The hole was still big enough for air and water from a hose but not full flow.

with the the fitting out it was a good time to measure the thread
The square end that fits into the block looks like 1/4 18 NPS (60deg)
The water pipe end is not the same! I think it is 1/4 19 BSPF (55deg)

Can someone check these threads please

I was chasing the backing nut for the pipe fitting in the exhaust pipe. My local nuts and bolt store measured the fitting thread as 1/4" BSPF and sent me across the road to a hydraulic hose as they didn't stock the fitting. The back nut I purchased fitted both threads on the fitting. (The F on the end of BSPF designates FUEL which means that it is a parallel thread.) I measured the thread on the end that fits in the block as 18TPI, the same as Nudge, but the back nut fitted easily. Maybe because the nut is so thin, it screwed on regardless of the difference, or the thread is really 19TPI. I don't have a 19TPI gauge to measure it.

This list appears to be four years old, isn't it about time there was a full list of all Seagull threads/bolt sizes on here so no one has to guess or spend time measuring or wasting the shopkeepers time by walking in and asking "Have you got one to fit this?" and he has to go trying everything in his shop finding it?

This list appears to be four years old, isn't it about time there was a full list of all Seagull threads/bolt sizes on here so no one has to guess or spend time measuring or wasting the shopkeepers time by walking in and asking "Have you got one to fit this?" and he has to go trying everything in his shop finding it?

Yes you are correct .. So have you worked the rest of them out yet? If so I will add them to the top of the list.
The list was started because I had worked out the threads that I needed then as others found out the rest they were added.

Your turn!