July 2011

Issue link:

Contents of this Issue


Page 49 of 171

benchwrenching By Paul Glaves Where Did They Hide The Valves? SOMETIMES A MECHANICAL JOB turns out to be a bit more tedious than expected. It is now early May and we are leaving for the International Rally in Bloomsburg, Pennsylvania. Admittedly we are taking the very long way to get there. Voni’s F800S was due for a valve clearance check and adjustment as necessary. It was time to get out the repair manual and dig in. This was, to me, a new procedure on a new bike. I have always believed that on BMW motorcycles, maintenance is 90 per- cent fundamental mechanics and only 10 percent model specific. I still believe that, but the 10 percent can sometimes be quite entertaining. The F800 series motorcycles are part of a new trend in BMW motorcycles. Unlike either the horizontally opposed twin-cylin- der bikes or the on-their-side classic K bikes, the F800 series motorcycles have a more or less vertical cylinder orientation with a bit of forward lean. This fundamental engine orientation has been in use for a very long time, including many early British, Japanese and other motorcycles. It is also the basic orientation used on the later K series BMW bikes, including the K1200, K1300 and now the K1600 six-cylinder motorcycles. It isn’t just the engine orientation that makes these motorcycles different. That isn’t a fuel tank ahead of the seat. That is the battery and air box and several other things. The fuel tank is under the seat where the battery and air box and several other things used to be. To those accustomed to maintaining their opposed twin or classic K bikes, these bikes are different. I think we need to get used to that. As with many current BMW models, step 1 is to remove the body pieces to work on that which is hidden beneath the plastic. To simplify re-assembly I use a muffin bak- ing pan, which I abducted from the kitchen. It has 24 spots to keep fasteners segregated as I go. For big jobs I dig out a second muf- fin pan I keep in reserve. BMW uses enough different length fasteners of the same diam- eter, and different head styles that keeping track of them is important. 48 BMWOWNERS NEWS July 2011 made my Torx driver either too long or too short to conveniently loosen them. But perseverance prevailed. There were several Aha! The air box. I know the valves are down there somewhere. When the plastic body panels are off, you can proceed. For a valve check or adjust- ment on the current BMW upright-engine motorcycles, proceed means try to find the valve cover. This requires that the battery be removed. Then the air box can be removed. Three hoses several electrical connectors must then be disconnected. To keep track of what will need to go back where it came from, I take a lot of digital pictures. They are not artwork for sure, but do provide a useful reference if needed. It looked to me as if I could skip a couple of steps outlined in my Haynes manual, includ- ing “dismount radiator” and “remove front heat shield.” I’ll comment more on this in a moment. As soon as the air box was removed, I could at least see the valve cover. The forward fas- teners were difficult to access. Had the bolts been Allen head bolts, it would have been easy to use a “ball end” Allen wrench to remove them. But they were Torx head bolts and their location additional impediments to the removal of the valve cover. First the throttle cable needed to be discon- nected and moved out of the way. Then the clutch cable needed to be discon- nected and moved out of the way. Finally, portions of the wiring harness and some connections needed to be moved out of the way. The process would have been a little easier if I had believed the Haynes manual and just moved the radiator and heat shield, but I didn’t know the end of that tale yet either. Eventu- ally I was able to squeeze the valve cover out. Clearance between the cover and the insulation along the frame rails was scant, if not nonexistent. Then the final surprise. The Haynes manual was correct. I couldn’t find any way to insert a feeler gauge to measure the exhaust valve clearance except by reaching in from below and ahead of the engine. This The valve cover is visible once the air box is removed.

Articles in this issue

Archives of this issue

view archives of BMW - July 2011