A helecoil is probably the best way to fix it. It will use the stock plug and the threads in the case will be a bit stronger than stock.

 

Any place I can go on line to learn about the helecoil repair? I've never heard of it before.

Thanks

 

Okay, I cut the new bolt and put it in. When it got to the tightest point it slipped just like the old one. I'm guessing that the top thread in the case is stripped. Someone suggested I use teflon tape or silicon. Would either of those work or would it just bea temporary fix?

Barry

 

Go to:
www.cyclewearables.com/helicoil/

Another choice is just google Heli-Coil or Helicoil and you will get more places than you care to see.

Before you jump in and buy some.....be sure to read about the helicoil and understand what is involved with the installation.
It amounts to drilling the next size hole and tapping that new hole. Then the helicoil insert screws into that hole. It looks like a tightly wound coil spring insert.
When the insert is bottomed in the hole, you turn the tool backward. This make the spring shape expand outward which holds it even tighten in the hole until the drive stub (that your install tool has been grabbing) breaks off. There you go, you have a non stripable hole forever.

The problems you will have:
1) you are already at 1/2 inch. This means you will be dealing with something like a 9/16 drill out job, followed by a tapping exercise. Holding a close to 9/16 drill freehand is not an easy task. But, the worst thing is the next item.
2) Since it sounds like the hole under the flywheels, you will have zero room when you bust through the aluminum crankcase before you will quickly hit those wheels. Same problem with the tap, no room inside to advance the tool so the aluminum is threaded completely.
Now if the drain plug in question was the transmission instead, then things look better because you can remove the transmission guts fairly easy to go at it with your drill and tap, then get all of the metal frags out of there before reinstallation of the trans.
You might want to take this one to a good indy shop. Someone who does Tig welding and is better than just good at it. They can offer other ways to fix this. Myself, I'd just weld a plug in the hole and be done with it. The plug has no practical use that I can see. If the base loads up from sitting without being run for a long time, just let it puke the oil out the breather when you crank it up.
I do not know why in the world H-D ever put the plug there. Older bikes don't have this.

If it were up to me, no aluminum threaded hole in the entire would be allowed to leave the factory floor until it had a helicoil installed in it. Period. You cannot strip a helicoil, once you get it installed.........pg

 

Barry,
Pinion has good advice as usual but he prefers to do a good job. When I was broke (and I mean broke) I had the same plug strip. I made sure the opening was cleaned and dry (as well as the plug). I then used (God forbid) J-B Weld on the plug and a little extra around the head. Ran like that for a couple of years until I fixed it. When I wanted to get it off I just hit it with a torch. The J-B Weld becomes powdery when hit with direct flame. Bubblegum fix for sure but it worked for me.

 

Oh-o-o-o, that hurts! Ha-Ha. Yes, I'm always thinking of cutting no corners I guess. Cal is correct in saying that what I described was certainly not cheap, but on the otherhand, if you can get a guy who is good with a Tig torch, he could weld an aluminum plug in that hole in no time and I think it may be cheaper that one would think.
If the JB Weld will hold, then that's all you want it to do. That would certainly be the least expensive. The last thing you want to have happen is for the plug to fall out while you are riding. That would be the bike's last cruise if it were to happen, so think it out carefully..........pg

 

Well, I'm kind of at a loss. I am thinking of going the JB Weld route for now for time and convenience sake. My main concern is that if this thing comes out, I'm probably going to get oil under my back tire and crash. I've never used JB Weld before. Which of their products (http://jbweld.net/products/index.php) do you think would work best?

 

I use the J-B Weld not the quick. The quick does not set up as strong in my opinion. If at anytime the J-B fails this is what will happen. You still have to thread the plug in, correct? It does not fit in there loosely it just does not tighten all of the way. I had the same thing. If it was going to fail I did not think the plug would fall out. I still feel it would develop a leak I would notice long before that. You said you were going to make your own plug. Make sure that puppy does not hit anything on the inside of case before you set it. Make sure the plug and area is totally free of oil before you go for it or it will leak right off. Remember, this is a temporary fix, how temporary is up to you.

 

I cut the new bolt to the same length as the old one, so I don't think that will be a problem.

I went ahead and bought the regular JB Weld. I coated the threads and underside of the bolt head. I then putthe brass washer on and put a thin coat on it, then hand tightened it into the case. Hopefully I put enough stuff on.

I had everything dry until just before I went to screw the plug in. I noticed some oil, dried it up with a towel, and went ahead and screwed the plug in (as above). I know that the flat part where the head meets the case was dry, so hopefully that will be enough. I might go out later and put some more around the sides of the head just to make sure.

Thanks everyone, for all your help. I'm sure I'll be asking more questions very soon

Barry