Featherweight plug connector question.

[edzell]

Hello, I'm new on this board (and virtually to Seagulls.)

Cleaned up a donated Featherweight and had it running in a tub last season although I couldn't make sense of the spark plug connector. I must just have been lucky - this year it won't make reliable contact at all. I can create a good connection of my own but it's not "water resistant" - besides I'd like to know how the original worked. Maybe I have cannibalised parts, or lost a piece; something's missing - maybe just my intelligence?

I'm attaching a photo and long-winded explanation as follows:

Referring to the photo, the only (unsatisfactory) way I can assemble this is:
- Small black thumbscrew with brass piece (lower left) goes through hole in top of hard plastic housing (upper right, shown inverted,) is secured inside by white plastic circlip, lower right.
- Brass thumbscrew piece is internally threaded to fit plug.
- Plug lead (upper left) slides into tube of hard plastic housing with rubber boot, not shown..
- Hole in plug lead can now be maneuvered to lie over thumbscrew brass piece but nothing secures it there - it can wobble around. Brass piece can barely protrude through it.
- If you're lucky all the bits will now line up to screw onto the plug and the engine may run BUT probably not because the plug-lead-end can still wobble, is not held securely in contact with anything.

Note: The hole in the plug lead end is too small to fit over the larger diameter of the brass piece above or below the circlip (where it wouldn't make sense anyway, still wouldn't be held in proper contact?)

Info, advice & comments welcome!

[Charles uk]

Ignore the bakerlite plug cover & fasten the plug lead to the spark plug with the black thumbscrew, now you can see the theory. Now do it using the cover, it's just a bit more fiddley

[edzell]

Thanks for the response,

Ignore the bakerlite plug cover & fasten the plug lead to the spark plug with the black thumbscrew, now you can see the theory. Now do it using the cover, it's just a bit more fiddley

Done all that before. The thumbscrew will NOT clamp the plug lead against the plug. Hole in end of plug lead is far too big, though smaller than big diameter of thumbscrew brass. It would have to be smaller than the very puny tip of the brass piece for that to work and the connection would be structurally very weak.

As far as lining everything up is concerned, "Fiddley" would be putting it mildly. Wouldn't want to be doing it hanging over the stern in choppy water.

Do you have a similar setup yourself? Something must be different, or missing, from mine?

[Charles uk]

The hole in the plug lead metal tag is 4.65mm in diameter.
My new plug cap is exactly the same as yours but the thumbscrew is held in place by the plastic circlip.

[edzell]

Thanks again Charles

The hole in the plug lead metal tag is 4.65mm in diameter.
My new plug cap is exactly the same as yours but the thumbscrew is held in place by the plastic circlip.

DISREGARD THE FOLLOWING: IT'S MOSTLY NONSENSE. I'll reconsider & post again.

If I understand you correctly, your brass tag slides completely onto the brass part of the thumbscrew, past the circlip slot; meaning the hole in mine needs a little enlarging/forcing to fit. That would make sense except as far as I can see the tag will not be clamped firmly against any part. The thickness of the tag is too small so no clamping occurs. Maybe there should be a washer below the circlip. I'm just going out to check all this (half past noon here.)

Thanks for bearing with me here; please keep doing so.

[edzell]

The hole in the plug lead metal tag is 4.65mm in diameter.

Mine is approx 6.5mm. So is the dia. of the thumbscrew brass although very slightly larger. (May not have been metric sizes originally?)

My new plug cap is exactly the same as yours but the thumbscrew is held in place by the plastic circlip.

Yes, that's clear but where & how does the brass tag get trapped for electrical continuity?
I'm using a D16 plug but presumably there's nothing unique about its dimensions.
Sorry if I'm being thick but something doesn't add up for me yet.

[Charles uk]

The thumbscrew pushes the tag down onto the sparkplug thread, just like a nut.

[Keith.P]

Have a look at the picture i posted.
http://www.saving-old-seagulls.co.uk/fo ... f=5&t=2026

[edzell]

The thumbscrew pushes the tag down onto the sparkplug thread, just like a nut.

Thanks Charles. That doesn't work for me because the tag hole is too big. Maybe someone modified it. I've got a temporarily usable connection using a washer but the whole arrangement seems a bit hokey. I think I'll be fashioning a more secure connector of my own.

Thanks again for the info.

[Charles uk]

solder a brass washer of the right size onto the tag.

[Vic]

What you have there looks correct.
Fit the the thumbscrew into the cap and fit the clip to retain it.
The lug on the plug lead then just fits (loosely) over the bit that projects through the clip
Tighten the thumbscrew onto the plug, making sure the plug lead stays in position.
The cap and the lead will remain loose and floppy, only the thumbscrew is tight
In use the thumbscrew will work loose so re-tighten it before every trip or it falls off the plug completely

Checked mine: The hole in the lug is only approx 5mm or 3/16". It just fits over the thumb screw.

[chris]

I stopped using the cap because it can be a pain to change in a hurry, I just use the screw that comes with the plug, the screw that is part of the proper cap has a habit of coming loose, and I know everyone will say what about weatherproofing, it takes a lot to stop them and i have been out in rough stuff and had no problems

[atoyot]

I stopped using the cap because it can be a pain to change in a hurry, I just use the screw that comes with the plug, the screw that is part of the proper cap has a habit of coming loose, and I know everyone will say what about weatherproofing, it takes a lot to stop them and i have been out in rough stuff and had no problems

A few notes FWIW -
* Use some of that clear spark plug "grease" found at auto stores. Some around here sell a little packet the size of a tea bag, also good for tail light bulbs & trailer hitch wire harness/socket.
* If the lead is lose, I second the idea of putting a small washer (brass, stainless) over the lead and then the cap/screw. No one will see it and it'll make good contact.
* Consider safety-wiring the cap screw in place. Drill a tiny hole or two, angled outward from the screw cap head. This pic shows S/S aircraft safety wire but even fishing line would do.

The nut is fastened with the high tension lead just so, where the weight of the lead trying to fall clockwise toward the earth keeps the nut just snug all by itself.

Of course if what you're already doing is working well in rough seas that's great.


-ted

[edzell]

Thanks all for the input. I'm now convinced of a couple of things:

- My HT lead has a non-standard tag at the plug end (hole too big).
- The original Seagull connection was less secure & less robust than I'd like.

I'll probably devise something of my own. The suggestion of using the screw that comes with the plug would be OK but it could be awkward to manipulate (and easy to lose) with cold wet fingers. I wonder what would be wrong with a push-on type of connector as used in cars nowadays, with suitable weatherproofing.

[Charles uk]

All types of Seagull ignitions don't like resistors in the HT areas.

I think they stopped fitting the Bakerlite Seagull plug caps in the 70's, so they are all at least 30 years old & that makes them very desirable, so don't rob any bit's off it.