Originally Posted by Iain Mac

There is the thick 50p shaped donut that is no longer available anywhere except secondhand, and a thinner round one used on later 4x4 Sapphire and EsCos models.



With the early one, the front section of the prop and the output shaft both go into a bush in the centre of the donut. On the later one, the donut doesn't have the bush - instead, the front section of the prop passes through so the output shaft can plug straight in.

You can use the later bush with the later front section of the prop, but you need to change the three studs on the back of the box that hold the donut. The bolts to hold the donut to the prop should ideally be changed for shorter ones too.

Or you can get an adapter made up like mine - it cost £95 + £75 or so for the new donut.