Ok, have just come back from the garage to see how things were going and things maybe improving.
The problem seems to be the valves or should I say "the valve seat has burnt out" or words to that effect. It doesnt mean much to me but he seems certain this is the problem so fingers crossed.
Just a bit of a wait now for the parts to arrive. Ill let you know if this works, hope this helps someone else if they expeience the same problems.