Oil galley plug thread size?

[CatatonicBug]

The oil galley plug at the bottom of the alternator is usually held in by the alternator cover. I know I have heard of at leas one other member removing that plug and threading the hole, replacing it with a threaded plug. Anyone done this, and can tell me what size tap/plug I should use? The o-ring has failed on mine again, and I'm tired of messing with it.

I read trbig's description of how he did it, but he just used 2 threaded plugs, and used the first one to tap the hole. I'd rather not go that route if I don't have to. He also didn't state what size plug he used.

[natemoen]

Ask him....

[DAVINCI]

I've done that, but it was long ago and I don't remember what size I used. If you're not in a hurry I'll have my motor apart in a few weeks and I can measure it. I did use a tap to cut the threads, though. BTW, be real careful doing this, right next to that plug is the feeder for the #5 main bearing. If you leave ANY chips in there, that bearing will be toast.

[CatatonicBug]

Ask him....

He didn't remember - besides, he's not on here much anymore...

I've done that, but it was long ago and I don't remember what size I used. If you're not in a hurry I'll have my motor apart in a few weeks and I can measure it. I did use a tap to cut the threads, though. BTW, be real careful doing this, right next to that plug is the feeder for the #5 main bearing. If you leave ANY chips in there, that bearing will be toast.

Thanks. Not a major rush, but something I want to do before the winter's over.

[DAVINCI]

OK, I'll let you know.

[cywelchjr]

He didn't remember - besides, he's not on here much anymore...

Yeah, but you know where to find him right? I recall that Randy did it too, and does remember, something about 1/2 inch size, non pipe thread and thread sealer. He also said he was not comfortable with doing it without the cases split because of possibly blocking oil to the crank. I would be really worried about that as well.

[CatatonicBug]

Yeah, but you know where to find him right?

Well, if he's not here, I can't find him. I have no desire to look elsewhere...

[natemoen]

Dang it Cy!

[natemoen]

Here ya go CBug

From Tod

Though I don't see any problem doing it with the motor in the bike, (You aren't going to get any better access to it with the cases split) Randy is right that you have to be careful. If you pull out that galley plug and shine a flashlight in from the bottom up, you will see the hole that leades up to your crank bearings. It's in that narrower section next to where your galley plug sits against. (*Edit... Randy saw Randy just posted that pic)

Before going this route, I would try a couple different, less permanent options though. If a new O-ring won't seal it, try soaking the plug and O-ring in brake fluid overnight to swell the O-ring.

Or, get some Yamalube/Tribond and clean everything extremely well with some brake or carb cleaner. Remove the O-ring and clean down in the grooves really well. Put some Yamabond/Tribond down into the groove, then install the O-ring, then put some more of the gunk all around the plug and then around the hole in the motor where that plug sits. Spin it in your fingers for a minute or two so it doesn't drip off and skins over, then install it and let it sit there overnight. I'd then cut a small thin piece of rubber and glue it to the inside of the cover in the spot that pushes on that plug just to help push against it and hold pressure on it.

From Randy

Dug through my toolbox and the tap I bought to do the plug is a 3/4"-10. So the plug is 3/4-10. i suppose you could use any thread pitch 3/4 plug and tap combo.

Here's a shot before I tapped the motor...notice the #5 main bearing oilway...only 3/4 inch in! Go REAL slow with the tap, there's not much meat on the case there and you will crack it if you try to tap too quickly.

[CatatonicBug]

Thanks!!