20 Most Recent 1993 BMW R 100 R - Page 3 Questions & Answers

if you can get the specifications they can be tested ( best done by a service center with the equipment) generally a clean using vinegar will remove the oxide build up that affects their performance unless it is a wiring problem in which case , replacement will be required be careful as there are 2 oxygen sensors in use one has 4 wires and is a heated oxygen sensor and the other is an oxygen sensor with 2 wires

Cold engine set valve clearance at: 0.10 mm intake or about .003" inch. 0.20 mm exhaust or about .007" inch. ---

Had the same problem with my R80RT 1986 model .Suggest to drain the gearbox oil ,if it looks like metal flake paint then definitely bearings . In my case it was the output shaft rear bearing , I replaced all the bearings (except the main bearing on the input shaft because to replace this one requires replacing the shaft as well many dollars) my bike had done 275k K/m (170k miles)