A friend brought me his 1993 R100GS with a problem. It starts and runs fine up to about 4500 rpm, but under load in top gear (passing or climbing a hill) and it starts to shake. Feels like one carb is getting starved for fuel. I pulled the bowls off to have a look see and found it had been converted to the independent black alcohol proof floats. These are not covered in any BMW manual, does anyone know the method for checking fuel levels and set up for these? Is it the same level as with stock floats, or do I need to buy a Bing manual?