Boxerworks.com

On my gallery, here's a online owner's manual for the R90/6.....

https://pbase.com/dwerbil/bmw_motorcycle_r90s_manual

Welcome! Looks like a fun project. Lots of archive information here.

It's normal. A boxer engine has a huge amount of crankcase compression as both piston come to BDC together. On the rare occasion I've forgotten to screw in the dipstick, the noise it makes on start up wouldn't let you ride off in that state. Did that once on the /7. Do it once and one will never do...

Kurt in S.A. wrote: ↑Sat Jun 07, 2025 1:30 pm But the bike runs well it seems in 1, 2, and 3rd. Guess I'm not really getting all the dynamics.

Kurt

Maybe when the bike is on the road/under load.

That happened to me on the '84 RS while on a weekend trip. Engine would flutter at highway speed. It was a slight tear in one of the diaphragms. Quick fix was to stretch the tear just a bit and use a drop of super glue. The next day, it got me the 200 miles back home like nothing had happened.

No didn't check rocker arm end float, never gave it a thought. Will check. Have the anti ringing inserts, interestingly MaxBMW consider them unnecessary? I never knew of the pillow-blocks and of 'pinching' them together when torquing the heads until I came across this forum back in the late '90s. W...

.....with a new series called Long Way Home. Ewan McGregor and Charlie Boorman are tooling around Europe, this time on older bikes - a Moto Guzzi and an airhead I've yet to identify; probably a R90. Problem with viewing the new series - one has to have a subscription to Apple TV. That counts me out ...

SteveD wrote: ↑Wed Apr 09, 2025 9:21 pm Try this.
Remove the large central nut at the steering stem.
Shim it with aluminium foil and refit.
If that helps, replace the nut as it's likely worn.
If no change, well, it hasn't cost anything.

The clunk isn't uncommon.

Sounds similar to .....Zen and the Art of Motorcycle Maintenance.

About the same thing happened on my '84 RS...new battery and the starter wouldn't go. Charge the (new) battery and it was good to go. That was a new one on me.

Great! Like me riding with a safety vest on - they'll either make you stand out more or make you an easier target to hit.