As mentioned last time, when rebuilding the top end of my R75/6 the replacement heads that I had for it had a few problems. The heads are from an R75/7, so are a straight fit onto my bike because I already have modified the  valve gear to a later specification than that originally fitted to my series 6 bike.  I have no idea of the mileage these heads have covered, so they were stripped for inspection and cleaned before anything was done with them.  I have a small lever type clock gauge which I used to check the valve guides for wear.  These at least were well within tolerance, so we had a good start. Next the valves.  Both inlet valves looked good and a light lap in with fine paste produced a good seating surface.  The exhaust valves were a different story.  They appeared to have been seating on a knife edge thin ring around the valve (see the before and after picture below).  When running my finger nail across this, the nail actually clicke...

This article was originally published in the paper version of Real Classic Magazine in November 2017(There is a link to their web page on the links sidebar).  The magazine version of this article is much better laid out than I can manage here, but the info is the same.  If you are considering long term ownership of an airhead, then hopefully a) you won't have a 1974 bike, and b) there might be something in here that you find useful.  Since I recently wrote about a starter motor problem I had had with this bike, I thought you all might enjoy the bikes back story.  It's a bit of a love/ hate thing.  Enjoy. _________________________________ There has been a lot written about BMW airheads in the last few years.   So, in the spirit of if you can’t beat them, join them, here are a few thoughts from my own perspective. Firstly, a bit about my own bike; a picture or two of which might even decorate/ desecrate these pages.   I boug...

This article was originally published in the June 2010 edition of Minnesota Motorcycle Monthly.    http://mnmotorcycle.com/ .  The bike had featured in the magazine before, hence the familiarity of the first few paragraphs.  The whole thing was done as a reply to a 'Geezer with a Grudge' column. _____ After major surgery on its cylinder heads and a whole series of maintenance tasks and modifications, my old R75/6 lives again.   The last of its original oil seals in the bevel drive have been replaced, and I have fitted a later swinging arm with a shock absorber in the shaft drive.   A new horn replaces the feeble original, and an up rated alternator now gives me scope to plan a whole new series of alterations.   All in all it’s been a busy winter, but a month or two of commuting has shown that things have bedded in and my confidence in its reliability has been restored.   You may wonder why anyone would want to be bothered wit...