the bike im trying to identify is an older bmw with 2 cylinders.it has only 1 bolt though the valve cover and uses mechanical slide carbs.it has a full padded seat and the frame number isnt anywhere near the stearing stem but is on the left side near the shock.the frame and engine #s match up 43126 ive looked the number up and it shows i have an r42 but i dont think its that old and it looks nothing like it.it looks alot like the r 51/3 models but i cant match any numbers..lack of resources.any help would be awesome.