I considered this for days but I'm pretty sure I would be over my head. Someone is parting out a BMW F650 GS which has the fuel injected rotax 650. Throttle body, computer, wiring harness and fuel pump are all up for sale as well as the engine. From what I read up on the computer is altereable and BMW had various maps which most were leaned out for emissions reasons. The computer also functions as the cdi. Diving deaper into the comp there are more parameters that are altereable but it's not a simple operation. The throttle body is probably worth owning to adapt to another easier to remap computer but will it flow enough air on a modified bike? could it be bored? I don't have time for a project of this magnitude but hopefully someone here could pick up a good deal.

 

Here is a link to the engine, it seems like it would be an interesting project. Aren't the F650s geared higher than the DS also?


http://cgi.ebay.com/ebaymotors/ws/eB...tem=2456540853

 

I don't know much about the motors other than they were supposed to be the same at the time the DS was developed. Many bike motors that go into quads have beefed up output shafts due to increased stress. I would have to guess that the gears would be the same ratios with the difference made up by the sprockets.

 

the gearing is different.

the head is a new design for the fuel injection. the intake port & throttle body angles upward. it doesn't look like it would work in a DS frame.