curious- how many parts to the crankshaft

Yes, there are engineering workshops that can realign the crank phasing. I suspect that it requires some heat and a press/puller.

You'd need a new crankshaft. 

Still curious how many pieces.  It would be really cool to see a video of the assembly in the factory, but they might consider that confidential info. 

hi Russell

The press fit crankshaft design is very common on motorcycle engines.  It is used to keep the engine small and light.  

There are a number of parts to the crankshaft, 10 in number.  There are the rods, 4 or course.  There are 2 link bars to join the nose forging to the rods and center forging.  Another joins the center forging to the mag end forging and then there is the camshaft timing gear that is pressed to that end.  The pins are slightly tapered where they are pressed into the links and put together with some Loctite at the time of press and alignment at the factory.  While it is possible to take the crankshaft apart with a large press there is no practical way to rebuild the crank in thats once taken apart there is always the risk that the press fit on the pins may be compromised and not hold as well on a second pressing.  For this reason Rotax no longer rebuilds crankshafts and only sells new.  Each crankshaft after assembly is tested for torsional twist resistance and must pass within tolerance.  I am unaware of any aftermarket company that has such equipment.  

For high power on the type 915 engine (100 KW or 141HP) the crank rod pins are larger and the pins are a special rolled process to strengthen and reduce torsional influences at high power settings.  

Cheers

Thanks for the fantastic answer! 

Rusty