thread repair help

[DimitriT]

Last year I cross-threaded the #2 spark plug on the 550 and managed to make a total mess of it. To make a long story short I have a steel thread insert in there and it seems to work well. The only problem is that when I remove the plug the insert comes out with it. The installation instructions suggested I use high temp RTV but this doesn't seem to really hold it. It seems the bond between the plug and the insert is much stronger than the bond between the insert and the motor. I've tried applying anti-sieze to the plug but that didn't entirely help.

I really want to get this fixed and I plan on having the top end off soon to take care of a leaking oil seal so here's the opportunity. Should I try JB Weld? A high temp epoxy? Do they have a thread locking compound special for this?

[chiphead]

Try the red Loctite stud and bearing mount and let it setup. I've had luck with this before.

[Steve]

If the red Loc-tite does not work, you say you are going to have it apart anyway, so take it to a shop where they can fill in the hole, then re-drill and tap it correctly. Hardest part of the job is removing the head, and you will have it off anyway, so...


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[DimitriT]

If the red Loc-tite does not work, you say you are going to have it apart anyway, so take it to a shop where they can fill in the hole, then re-drill and tap it correctly. Hardest part of the job is removing the head, and you will have it off anyway, so...


.

Steve,

what do they fill the hole with and how much do you think a job
like this would cost?

thanks.

[Planecrazy]

Another alternative is to use a product called HTS-2000. Once you've used this stuff to fill the hole you can either drill and tap it yourself or have somebody else do it for you. Check out the video on their website for a demonstration of how it can be used.

Good luck with it!

Regards,

[Steve]

Several years ago, I had a mounting boss break off of a Toyota Corolla head. Took half of one of the header-mount holes with it. I took it to a machine shop, they built it up by heli-arcing more aluminum to build up the area. When they were done, they milled the surface to match the other header mounts, then drilled out ALL the intake and exhaust manifold holes and installed Heli-Coils for me. This happened about the time that some of our bikes were on the boat from Japan, so I can't really remember how much it cost.
I don't remember it being prohibitively expensive, though. 8-[


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[Nightmare]

Another alternative is to use a product called HTS-2000. Once you've used this stuff to fill the hole you can either drill and tap it yourself or have somebody else do it for you. Check out the video on their website for a demonstration of how it can be used.

Good luck with it!

Regards,

WOW! That stuff looks really cool!! Wish i could use that to repair the threads for my oil pan...

I learned a very good lesson about torque wrenches that day... coffee before torque. I sort of set my wrench to 24ft-lbs instead of 14 and pulled the threads out of the block. I don't think it would be overly easy to turn the entire bike upside down to pour/brase moulten aluminum into the hole so it looks like drilling and retapping is for me...

[Planecrazy]

WOW! That stuff looks really cool!! Wish i could use that to repair the threads for my oil pan...

I learned a very good lesson about torque wrenches that day... coffee before torque. I sort of set my wrench to 24ft-lbs instead of 14 and pulled the threads out of the block. I don't think it would be overly easy to turn the entire bike upside down to pour/brase moulten aluminum into the hole so it looks like drilling and retapping is for me...

How about this? Take a small piece of plate aluminum, drill and tap it for the drain plug, then simply lean the bike over (with proper support, of course, so you don't break anything), and tin both surfaces with the rod so that you can attach them together (like soldering a contact on to another electrical component)?

The advantages of a repair like this are severalfold. First, you can use a thicker piece of aluminum for the patch, which will hold more threads and be less likely to strip in the future. Second, the drilling and tapping takes place away from the bike, so no fear of metal filings getting into the motor. Third, you don't have to worry about filling a large hole ... only bringing the two pieces up to a temperature where they'll simply bond together.

Just a thought, kind of like that lap joint they demonstrate at the beginning of the video...

Make sure you completely drain the fuel tank and THOROUGHLY degrease the engine before leaning over the bike and applying and open flame to the pan.

Regards,