7/16 is 12 mm and 3/8 is a hair smaller than 10 mm.11mm? That's between the two.
fraction mm
3/8 9.5250 25/64 9.9219 13/32 10.3188 27/64 10.7156 7/16 11.1125
I can measure mine with a caliper but not until next weekend (Aug 24).
My boat is 90 minutes away. My trip to the lake today has been delayed until tomorrow, or perhaps until Tue or Wed.Very gracious offer! I’ll take you up on it. If I figure it out beforehand I’ll be sure to post.
The photo doesn't match my pin at all. Mine is much shorter, smooth with no threads, with a hole drilled at one end for a split ring or cotter pin.The pins are for sale in the Parts Store. Goose neck pin
Ahh, there are two pins. One for the vertical hinge and one for the horizontal.The photo doesn't match my pin at all. Mine is much shorter, smooth with no threads, with a hole drilled at one end for a split ring or cotter pin.
It measured 10.04 mm. That's not very close to any imperial fraction so it seems it may well be a metric size: 10mm.
Bill
Your original post mentioned you tried a couple different size bolts. The mention of a bolt reminds me of this story. We were on a H270 in the middle of Haro Straight, between the US and Canada, when we heard a little tinkle sound of metal falling on fiberglass and immediately after the boom came loose and started thrashing about. The boom was attached to the gooseneck with a bolt and simple nut. If you can't find the proper pin with a drilled hole for a cotter pin or split ring, at least use a lock nut!