Well, between too thick a sealing washer, using too big a torque wrench, previous wear and my own ham-fistedness, I badly stripped out my fork oil drain plug on my left fork.  Like, reamed it out smooth bad. 

I somehow managed to salvage the right plug.

What's my best remedy? Order a Time-Sert? Time to go get that tap & die set? Any better options?

As an aside, nearest I can tell the fork oil capacity for an '85 K100RS is supposed to be 380ML after a full teardown. This sound right?

If you're interested I'll sell you a pair of 85 forks for $100 plus shipping. (Which shouldn't be too bad since I'm in Washington.)

duck wrote:If you're interested I'll sell you a pair of 85 forks for $100 plus shipping. (Which shouldn't be too bad since I'm in Washington.)

Thanks very much...I obviously didn't budget for it so let's call it "Option B" for the moment.  Nice you're so close!  

That is tough news.  Every time I touch those screws I hold my breath. 

I repaired a stripped out hole in the final drive for the speed pickup screw by inserting a pop rivet and then threading it.  It's still holding.  That was for a smaller screw though, and you may not be able to find a large enough pop rivet.

The only other fix I can think of would be to have a welder fill the hole and then drill and tap for your M6 screw.  Or possibly fill with that magic compound, JB weld.

zaubertuba wrote:. . . I badly stripped out my fork oil drain plug on my left fork.  Like, reamed it out smooth bad.

These look fun!
http://www.motobrick.com/index.php/topic,580.msg62505.html#msg62505
http://www.motobrick.com/index.php/topic,580.msg63494.html#msg63494

6mm Helicoil or take it out to M8. There's enough ally there to accept an M8 but you may need to cut a bolt to length. Putting in a Helicoil really isn't that difficult. The hardest part is ensuring that the tap goes in perpendicular to the hole.

Either way, you have to split the fork. Now, if the damper rod bolt refuses to come out - that's a complete b*st*rd of a job to remove. But there's ways round that too.

I used a 6mm Helicoil kit, which was a simple fix, but then had to source a much wider sealing washer to cover the wider-than-the-original-sealing washer's-capacity threaded area. No leaks after 5,000+ kms.

You could also use an O-ring to seal it. (Which is what the 4V Ks use.)

Thanks for all the tips, guys!  

In the end, I opted for the "longer screw" option and I did indeed get the screw to hold very tight...though I expect I'll have to do something more drastic at the next fork oil change.  

Bike rides great--except a new issue I'll make a separate post for--thanks again!

Just as long as the new screw is only the depth of the boss on the slider. There's only a mm or so between the inside of that thread and the valve housing ( part no. 9 here: http://www.realoem.com/bmw/enUS/showparts?id=0501-EUR-11-1983-K589-BMW-K_100_83_0501,0511_&diagId=31_0359). I took one set of forks apart where someone had replaced the drain screw and the replacement screw had dug a good gouge into the valve housing. Push it across too far and it will affect the damping.

Handy to know Dai.

Thanks.