I've found a R100GS which I am going to use on my R80G/S to get about 100km more range. Everything fits OK but I have a few questions as I go through the bits and pieces.
1) Is is possible to change the lock in the gas cap lock tumblers to match my ignition key? I cannot figure out how the lock cylinder would ever come out of there!

2) On MAXBMW fiche 51 25 2 307 140 is what I think I have for a gas cap. They recommend using a non SHED improved cap instead of the one I think I have. What is a SHED cap and why does it cause vapour lock? This tank has two hose outlets, one for ventilation and one for overfill so I don't get why the cap would cause a problem.

3) The petcocks on this tank have two metal washers in between the gasket 16121238924 and the lever. These are not shown on either the MAX or RealOEM fiche which both show the "new improved" petcocks. One of these washers is notched and the outer one has a tab on it. Do these get any special treatment like grease or ??? Any petcock assembly advice much appreciated. I'd like to avoid leaks.