Forum bmwbike.com

Today I ran my 1976 R75/6 for the first time since I bought it.
When I checked and adjusted the valves they were found to have no clearance.
I set them correctly.
When I started and ran the engine there is a disturbing clicking coming from the right side of the engine at idle,really didn't notice it above idle speed.
I pulled the right valve cover again and after it had got stone cool again I rechecked the valve lash and it was perfectly as I had previously set it.
Anyone got any ideas as to what the clicking is and how I might correct it?
Thanks,
Fred R.

I had a 75/5 back in the early 70's and with valves set properly when first started (I recall settings of .08 and .12) there was some clacking but as it warmed up the clearances shrank and it quieted down. Is your clicking loud, and is it present at idel after the engine is warm???

Maybe the rockers have too much play between the tower bolts. When you adjust valves, take a rocker that is not pressing on a valve and see if it wiggles back and forth between the towers that hold it. It should have no play, yet not be so tight that it cannot be rotated with fingers. To adjust the tightness, loosen the bolts holding the towers a little, and hit one tower or the other to pinch the rocker. Then retorque the bolts. This is better explained in a manual.

Fred,
You probably have too much lateral play between the rocker arm and the supports or wear on the washer, the bearing bolt and or bushings. Just closing the gap along the length of the rocker arm assembly might do the trick. On my R69S this is done by tapping the end of the bolt with only valve cover removed (provided wear is not too excessive). Otherwise try installing a new washer. Check the other assemblies and try to see if they are tighter. If they are then you have most likely found the source of noise. If it is wear in the bushings you will not be able to see it unless you dismantle the assembly.

Problems at idle clicking can be caused bij the carburettor. Clean it well. Specially look at the idle nozzle, a very little piece of dust can block it. The engine runs too arm.