Die Hexe Valve Adjustment

Since I've purchased Die Hexe a few months ago, the valves on the right side (sitting, facing forward) of her have been noisy. From various test rides, there is a clear audible difference between the left and right side of her. After changing various oils, filters and cleaning her up, I thought I'd peek inside to check. Duane's page on BMW motorcycle valve adjustment procedures makes it clear 'The main reason to do the valve adjustment is to check for a change in settings from the previous time.' Not having access to the previous details and due to the noise, I thought an initial baseline assessment (and adjustment if needed) would be useful.

Upon initial inspection, things looked good. The bolts weren't too tight. The oil flow looked good. The rockers had a simple, elegant (and downright cool) design to them.

Following Duane's procedure for valve adjustment and reading up on Snowbum's page for setting valves I felt like I had a rough idea on how best to proceed.

I turned the crankshaft back and forth until seeing the OT mark indicating TDC Top Dead Center in the side portal window. To figure out which side was ready for inspection / adjustment I rocked the crankshaft back and forth and rotated the pushrods with my fingers. The side that rocks and has pushrods that turn easily is the one at TDC and ready for adjusting (the other doesn't move at all).

Unfortuantely, spinning the rear-facing pushrod on the right side showed a noticeable wobble (perhaps as much as a 1/16 in) indicating the pushrod was bent. Ungh... Trying to see the positive in everything, i found comfort in at least determining the source of the noise ;)

The only guess is that the valves have been out of adjustment for some time and over time, one of the rods simply started to bend. With the help of my faithful assistant, I've put everything back together while I investigate this issue further.

New rods from ebay, and correct valve settings later, she's running again like a champ. The sound of happy tappers is similar to a vintage sewing machine (but with a hell of a lot more 'oomph!' ;)

Ready References

The following is a set of resources which I have found useful related to valve adjustments on my bike (and potentially useful for helping me replace my pushrods):


Special thanks to Charles Wixson for fielding my silling questions on the airheads mailing list.