Thanks David, I expected that the engine would have to come out again.

I don’t think the nipple can spin. It seems to rotate around the bottom, so if 0 degrees is top then it can move from about 105 degrees under the shaft to the equivalent position on the other side at 255 degrees. I’ve had a piece of cord on it to try to pull it upright and pulled pretty hard.

Is there a known problem with these conversions and if so do you know of a solution?

Many thanks
Graham