Leak from oil pan drain plug

[Guest]

Dear all,
Hope that you are well, these strange times considered.
My trusty GS850G has a leak from the drain plug in the crank case oil pan. It has a new plug and gasket, and it is tightened to spec.
I recently did a complete engine rebuild, and I noticed that the PO had installed one of these thread fixing springs (I believe that they are called Helicoils) in the oil pan drain plug threads.
The leak is considerable when it’s parked, and of course even worse under load, so it needs to be fixed.
I am looking at different types of sealants, for example:

1. Loctite 565 Thread sealant, directly on the plug. This is what Loctite recommends, but I am not sure if that will work with the Helicoil (if the helicoil is the problem)
2. Loctite 574 Flange sealant on the surface of the oil pan, around the drain plug opening, combined with a fiber disc.

Do you have any experience with the above mentioned solutions?
Is there other methods that you would recommend? I am a big fan of doing things by the book, but I am afraid that the service manual method won’t do it this time.
Please feel free to recommend alternatives to the Loctite product range. It is not readily available in Denmark.
Stay safe
Kind regards
Michael

[Nessism]

Neither of those Loctite fixes are appropriate. You either need to have a solid metal thread insert installed, drill and tap for a bigger plug, or get one of those "thread fixer" drain plugs which are available at most auto parts stores. These drain plugs have a taper shape and will cut new threads in the aluminum when installed. Needless to say, you need a new crush washer either which way. If you don't have one installed now that may well be the issue.

[Rijko]

I do not know how readily available GS850 parts are in Denmark,
but they are where i live.
I would replace the oil pan with a good one.

[bwringer]

Without seeing the pan in person, it's hard to tell whether it can or should be fixed. A "spring" style insert like a classic Helicoil is not appropriate for a drain plug or any application that needs to seal or where the fastener will be removed and replaced repeatedly; you need a solid metal insert. The spring inserts are strong, so they're fine for many applications, but can't make a good seal and they tend to come out when you remove the fastener.

Fortunately, since the thread is the same as a common spark plug (M14x1.25), you can easily find solid insert kits at any auto parts store. (Confusingly, "Helicoil" brand makes some of these solid insert kits.)

What we don't know sitting on the other side of the planet is whether there's enough remaining aluminum in the pan after you remove the coil to drill and tap for a solid insert. There are several brands and retention systems, and several thicknesses available.

Personally, I'd find a good used pan from fleaBay or at a motorcycle junkyard that has not had an insert installed, then install a good insert with positive retention, like a Time-Sert. Use a drill press to ensure that everything is nice and straight. Any machine shop would be able to do this, too -- as I mentioned, it's the same thread as a common spark plug size, so they'll have everything on hand.

[Gorminrider]

I always try the easiest stuff first...without damaging anything.

If you can torque it to specs, the thread might still be serviceable, even if the threads must be pretty loose to drip like that. (Consider looking for a bolt that fits tighter without reshaping the threads. DO be sure it is the bolt and not a crack or a tiny river from somewhere else entirely)
-I tend to avoid goops if I can, so first I'd just cut a thick-paper gasket with a close fitting hole punched in it.(karopak brown paper type) to try. If you have the white nylon washer that sometimes come with the bolt? put that on top of the paper as it widens the bolts contact area per compression a little... but adding washers will reduce the thread penetration a little. Next, try a bit of silicone rtv stuff on the paper

[DKGS850]

Dear all,

Thank you for your input. Highly appreciated.

Looks like I am going shopping. Either for a tapered drain plug, a new oil pan, time-cert solid incerts or karopak paper and silicone rtv sealant.

Might not be so easy in my neck of the woods. Wish me luck

Thanks again

Best regards,
Michael

[rphillips]

Hey DK, my vote goes to a replacement pan. I don't know about Denmark, but I just looked on ebay here & there are 80 of them listed there now, from $11 & up. I just feel more comfortable with good orig. un-repaired stuff instead of stuff like what it seems you're dealing with now. Just my opinion. Good luck

[Gorminrider]

I agree. Replacement parts in good condition are nice but meanwhile, a fix can keep you interested in the bike while you cast about for a ggod part at a reasonable price.

"Plumber's string" might also work fill the thread gap. It's just strands of white cotton string applied to the threads. It'll last quite well but will need replacement every oil change.

[mrbill5491]

Dear all,

Thank you for your input. Highly appreciated.

Looks like I am going shopping. Either for a tapered drain plug, a new oil pan, time-cert solid incerts or karopak paper and silicone rtv sealant.

Might not be so easy in my neck of the woods. Wish me luck

Thanks again

Best regards,
Michael

Threaded steel insert, end of problem.

[rphillips]

Congrats, well done. I love happy endings