I don't understand, just put it together like in the diagram. What problem are you having? All Horzontail Minarell's motors take the same crankshaft. Whay is yours different? Please explain more clearly.
If this is the normal Multivar 51 7075 or 51 7075T, then you've got 2 spacers in the kit a 2 mm and a 5 mm. If I'am right you need to use the 2 mm ring.
This spacer is necessary because the front and the rear pulley will be in one line (the Malossi Multivar and it' hub is different size then the original one)!