Thanks for all the help so far guys.
I bought the engine & controls complete but I'm wondering if it's a wiring issue. I have the multi pin plug connected at the engine end plus four wires tan to tan, green/white to green/white, black/white to black white also a blue/white connected to an all white wire which was the only one left.
At the control box end I have spare a grey (other grey connected to rev counter & working) a brown wire with a blue stripe and also a tan wire with a female bullet.
Any ideas gratefully accepted as the engine seems to run ok ?