IIRC Rotax bits are spendy & I have a vague recollection that these broke the frame, which was basically an ETZ251 item. That might have just been the early versions that looked like an ETZ251, though. For me that has already gone above what I would be interested in "investing" - not a model that has ever come up on my radar.

I am going to the MZRC AGM this weekend (for once it is local-ish) - could ask around if there are any Rotax engined bikes present to find out more "foibles" from the owners if that would help ?

Nigel B.