Originally Posted by Reno
Hi, my 'fixer upper' project has no bungs. Its an 80s (I think) zodiac pro 5.3 and the thread is quite 'fine' compared to what I'm used to. internal is 19.5mm.
If anyone can tell me where I might be able to find them, I'd appreciate it. I'm in Melbourne Australia.
It looks the same as used by Mercury/Quicksilver.
I've no Zodiac experience and can't give you a definite answer, the usual way to determine a thread is to measure it and use metric and imperial thread gauges then compare with data from Zeus tables. With pipe threads it's harder if the external thread is tapered. A clue is it's on a pipe lol.
I think the probability is that it is 1/2" BSP, 14tpi but it's a moot point when they are probably all the same on various Zodiac craft and other makes also. Just go to a reseller and get one ordered?
P.s. the Americans use NPT instead of BSP.
Last resort is to change the socket for one like this here: