Hello all.
I have an engine noise on my 1989 K75, its in the lower rev range, from tick-over to, say, 3500 revs?, its a rattle with a bit of knocking, I did think it was the cam chain, but no such luck, have replaced all parts, and still the noise persists.
After listening to the engine again, very carefully and with the help of a long handled screwdriver, to listen through, I am now sure its coming from the rear of the engine.
Pulling in the clutch makes no difference at all.
After reading a previous thread on here,
http://www.motobrick.com/index.php/topic,6465.0.html, a light has switched on after reading the post from Kyle10, where he writes about changing the backlash eliminator spring on the output shaft on his K, I guess a K100 as Kyle mentions to replace the rubber dogs.
So I took another look at the Clymer manual, fourth printing 2011, on page 130, oil pan, lower crankcase half and output shaft, it states there was a BMW service information bulletin - October 1988 no 11 037 88 (2289) revision, if there is a distinct noise coming from somewhere between the crankshaft and the output shaft gears, there could be a problem with the springs in the output shaft.
They describe the noise between a whine, rattle and knock, usually in the lower revs.
Not sure if the above applies to both K100 and K75?, I see on the drawing for the K75 output, balance, shaft, Haynes and Clymer, there is a spring between the drive gear and anti backlash gear, also a diaphragm spring (early models)/spring washer on the other side of the anti backlash gear.
Have I found my problem?, has any one had any experience of this?, where to get the parts from in the UK?, any other ideas?.
Sorry for such a long post!, its driving me mad, do not want to ride K75 anymore, until I can sort it out, just in case something might go bang....
Motorcycle also seems to vibrate a bit, well, seems more than I was lead to believe a K75 should do!...
Thanks,
John