Thanks for your reply,
@Mr TwingoIt is a clutch motor. The machine is a 'Typical' machine, which is a Chinese knock off a Brother. I bought it new about 8 years old and I used it perfectly happily until the motor burnt out. That may have been down to the amount of heavy work it was doing. Upholstery and curtains and some leather work. I really didn't notice any different between it and the Brother I used to have so was quite happy with it.
When the motor went I did quite a lot of research on the web and found a company (in Manchester I think) who said they had the right motor for it. Mr Crafter is an engineer (although not of sewing machines) and didn't see a problem with replacing it after he spoke to the provider I had found.
But now it goes at two speeds, stop and wizzing. No variation for a slow start which makes it unusable.
Now that the football is over I can get him to have a look at the video, or does this just apply to a Servo motor?