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...

 I have owned my BMW R75/6 for many, many years now and have always had something of a love/ hate relationship with it.  Get it going well on a long run and all is right with the world, but despite the image that BMW are keen to portray, it has been less than reliable over the years.  I must point out that not all of this unreliability has been BMW's fault.  For example, I have been through two Boyer electronic ignitions over the years, and as mentioned in the story link below, had an oiling fault caused a previous owners attempt to fit an oil pressure gauge (more on this particular fault shortly).  There has been one nagging issue that has been in this bike throughout though, and it bugs the hell out of me. The bike's engine has always made more noise than a bucket load of angry rattle snakes!   I have written about this elsewhere, including here:  Living with a 1974 BMW R75/6 (oldandireland.blogspot.com)  in a story first published in Real ...

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...

There are advantages to running an old bike that was in production for over 25 years, especially ones as popular as the BMW Airheads.   For example, parts supply is good, and many parts were updated or improved over the years.   Often these can be retro fitted to older models either directly, or with a little ingenuity.   As an early example of the breed, my 1974 R75 thus has scope for improvement in a number of areas. Take starting.   On cold mornings, pressing the starter button would produce only a lazy response from the engine.   The reason for this lies in the technology of the time as well as in the bikes design.   The original starter motor in my bike (made by Bosch), used electro magnets.   This meant that to get the bike to go the starter motors coils had to charge up whilst still leaving enough current in the system to produce a decent spark at the plugs.   The compromise here is that to leave enough juice in the battery for t...

Let’s face it, when you are buying second hand it pays to be cautious and to look for faults that the buyer may not have declared.   I have no problem with this, although I do try to be as honest as I can when selling anything.   What I do have a problem with are undisclosed problems that would be dangerous, but which would be impossible to find on any inspection without both prior knowledge of what to look for, and disassembly of the item being bought. Old and new sprockets from the Funduro.  The gearbox output shaft should be a good fit in the splines shown on the new sprocket on the right.  Instead its splines wore quickly to almost non existence. If you have read my last two motorcycle related posts here, you will have followed the tale of me buying and fixing up an old 1994 BMW F650 Funduro for winter transport.   You will also have read of the numerous faults that these bikes are afflicted with and the ones that I suffered.   I have no...

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...