Hi Dave and welcome to the Forum,
Jon Pegler is the Mototrans specialist on here, and hopefully he'll be along soon. In the meanwhile (and bearing in mind that anything I say, Jon may later correct ...)
Dave L wrote:I have two question: firstly, is there a manual I can buy that covers Mototrans Ducatis, including wiring diagrams ...
As Hans. Not that I know of. Mototrans itself published owners' handbooks and parts manuals for its machines, and these contain a fair amount of basic information. But I've never seen a factory workshop manual nor anything similar from any after-market publisher. That said, at various times the factory did issue a number of Concessionaire Briefings, all in Spanish nat'. And there are at least two marque-specific books, these too both in Spanish.
Libros.jpg
So:
Technical manual: use the manuals that cover the Bologna bikes, plus the appropriate Mototrans parts book and owners manual. (Among the manuals, the Haynes is possibly not a first choice ...)
Wiring diagram: When you say you have a 1978 250, I assume you're referring to a Strada? If so, this is the wiring diagram from the parts book:
You can download a copy of the owners' manual here:
http://lamaneta.org/manuales/manuales/D ... 201254.pdfCome back if you need more ...
Dave L wrote: ... and secondly how do I dismantle the swing arm from the frame? It is seized somewhere and I can't work out where! The snail move around the frame tube but I can't move the long shaft with the bars going through it at all.
You've lost me here, Dave. I normally think of the snail cam being at the axle end. Are you saying that your bike has the concentric chain adjuster blocks at the frame end of the swing arm, like the 860?
Eccentric.jpg
Saludos
Craig