Boxerworks.com

Yesterday I had to pass a minivan with a WFO pass. Upon completing the pass, all kinds of racket from the left . Yikes.

Investigating under the valve cover, I found 1/8" or so clearance on the intake valve.

I normally try not ham-fist the adjusters to avoid stripping, but I guess I need to put a little more torque on them. Re-adjusted and torqued them all last night.

was the lock nut loose?

Must have been not tight enough because the adjuster was in more than the exhaust. All the nuts on my adjusters require a little effort to spin. And no, the adjusters are not stripped. Maybe revving it so hight provided enough bibe to loosen it.

No signs of a bent valve stem and compression ok. Idles and runs just fine after a re-adjust and tightening. Re-check all 4
(82 R100 BTW )

I was thinking more along the lines of a collapsed lifter.... other thing could be, rocker arm bearings.
Or the adjuster was loose like you said!

Rocker bearings are good - no radial play to speak of, as well as axial play.

Collapsed lifter? These are solid right?

Also, I pulled the left intake push rod to make sure it wasn't bent.

The only thing I can conclude is that the nut lossened on me.

http://www.maxbmwmotorcycles.com/fiche/ ... d=03252011

cam follower #1

DON'T let me send you down a rabbit trail !! It could have just been loose!

Thanks for your replies. I must have been at fault for not tightening enough. But I still hold that our lifters are not hydraulic so a collapsed lifter I can't see. They have a space or hole so that acumulated oil from above can drain down to the crankcase, but they're not hydraulic lifters.

not hydraulic... but they can break. I've seen one with a hole punched right through it.