Replacing Gudgeons with one-piece gudgeon - Tap Size?

Hi - Im replacing the stock gudgeons on my son's 84 Hobie 16 with one one-piece like the new boats have. I also ordered a new set of gudgeon screws. What are the screw sizes, what drillbit and tap size do I need to put the new screws in with?

Thanks,
Paul Bommersbach

Pretty sure they are 1/4-20 machine screws

A 1/4-20 tap takes a #7 drill bit (13/64" is closest fractional).

Thanks Matt-

I just loaded your inflator and spray jacket in the truck, I'm leaving tonight for Clear Lake!

Paul

I'll see you tomorrow afternoon - I'm leaving in the morning.

Current gudgeon screws are 12-24

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Whoopsies!

In that case, the drill size is a #16 (27/64" closest fractional)

Did test hole on sheet of aluminum, slightly too large, came back in to post again, see it's already been answered, thanks matt and matt for the quick responses, now I can still get on the road tonight for nationals in Iowa!!!


Paul

MOTHER OF GOD!!!! A sure sign of the Apocolypse! Matt B, (aka Yoda), was wrong about something Hobie related. Get ready for the rivers to run red.

Actually, it's been a while since I've played with the gudgeon screws.

The last time I did, I increased the size to 1/4-20, which is the next size up from 12-24.

I couched my initial response, I did.

I switched mine recently. It is not a direct replacement since the hole pattern is slightly wider than the stock gudgeon. I didn't drill or tap the hulls since none of my original screws were stripped. I had to drill out the holes in the new gudgeon plate to 5/16". I also had to shave the shoulders of the hinge on the gudgeon as the stock #12 screws are pan head and too wide to screw all the way home. They foul the hinge. You might want to look for some fillister head or hex key screws instead. Don't forget to seal these holes since they go all the way through the hulls.