Hi 'unfazed', thanks for the reply...
Its got 19k on the clock but by the sound of the cam chain rattle when cold it may be more in reality.
It revs and pulls clean all the way to 7k and from 8k all the way to the red line. If i need to overtake at motorway speeds I need to drop it down a gear or two to take it above the 8k mark and it pulls great!
It does not misfire at all, it just feels like a severe lack of power and missfire between 7-8k rpm. If I feather the throttle through 7-8k rev range it picks back up fine.
Fuel filter and air filter were recently replaced with OEM parts in a full engine service at the same time the carb rubbers were replaced.
I've not done a compression check but it looses no oil, does not smoke when cold or hot, I could easily do this though so I may later.
There is no difference in issue when the engine is hot or cold.
I assume they checked the small inline fuel filter, I will ask later tonight when I see the mechanic.
Soooooo frustrating