GS 550 M rear sprocket confusion

[Guest]

Hi all!

I want to change the sprockets and the chain on my little katana. I chekd out in the garage, I have 42 tooth now! I found that the OEM rear is 50 tooth, at least on the net every place show that the oem is 50 tooth. 42 is too far from 50, can somebody explain why did PO changed from 50 to 42? Or is this from the factory? The bike has 80 000 kms, so I dont think it is the original sprocet. The bike is a 1983 GS 550 MD, (MZ model), with anti dive, and has a German plate on the frame neck. The Suzuki part system didnt know my bike, nor any parts supplier, I use the MZ models part numbers. So I can't be sure for 100% 50 tooth is the OEM.What you reccommend to buy? I didn't interested in max speed, so maybe OEM or a little more rev is OK to me, but what to look for?
Thanks for the help!

[Steve]

A stock sprocket has 50 teeth.

The PO might have done that in an ill-advised effort to reduce RPM at cruising speed.

.

[gabos666]

Thank you for the fast reply! I will return to stock 15/50 ratio than. PO is my worst enemy