Vintage BMW Motorcycle Owners

1974 R90/6. I inherited this problem. Anyone with experience with helicoil or timesert to fix the head on the bike? How about Back Tap?

Keith;

I recently put a helicoil in my R 75/5. I pulled the head to do it. (I tried one earlier on my R 90/6 and failed. I had to pull the head and take it to a machine shop. They bored it out and tapped in an insert.) I pulled the head to prevent any of the cuttings from getting into the engine. It is just not that much work to pull the head and the gaskets are not all that expensive. I put the helicoil in with high temperature Loctite. I have pulled that plug several times now and it is still holding.

Craig

Hey CB
My dad owned this R90/6 before me. He successfully coiled one cylinder and that repair has lasted many years.
Can you tell me why you think the one time failed and another time succeeded with your bikes? Looking for tips from your experiences before I take a swing. Leaving the head on while heavily greasing the cutting tap has good results from many. My dad never once removed the head nuts so you can bet they are corrosion welded on and will need to be cut off unless a miracle happens. Once that is out of the way, head removal is pretty simple, a reason I love the airhead tech. Thanks

Keith:
I'm sorry I didn't notice your post earlier. It wasn't a "helicoil" brand that I used it was a "K-D Tools" brand cylinder head rethreading kit. I think that I failed on the R 90/6 because I wasn't careful enough to put the piston at BDC. I think I hit the piston top with the tap and stripped out the new threads.

The insert in the R 75/5 eventually failed and I recently had to re tap it and put in a new insert. When it failed I could see flames coming out past the plug. I was able to ride 2-3 miles home on 1 cylinder. I did pull the head to do the re-tap.

Craig

I successfully did Helicoil the cylinder and my dad had done on the other cylinder. So far all is well. Hope yours goes well too.