Ran the engine and it was wheel spinning so the motor has good torque which is what I need so it can keep me going. Very hard to get used to the pedals going around on their own. Will have to learn how to get the knack of that. Problem is, the chain is pulling the pulleys out of position no matter how hard they are bolted down. The forces involved in chain theory is incredible. Been looking it up on you-tube. As a result of the research the best policy is to fit a pulley with a tension spring. So today I went to Marsh Barton and found one and fitted it with the aid of cable ties.
I have put a locking nut on the pulley and then loosened it enough for it to move. Tension has been put on the spring by cranking up the thick cable ties. Tomorrow will give the engine a run and see what happens to the chain.
The other problem is pedalling with the engine off. Turning the gearbox is sucking up a lot of leg power. Will have to remove the chain at times and only replace it if the landscape becomes too hilly which will mean leaving the engine on most of the time. But since the gearbox is new it may still need to be worn in.