When i originally wrote the above post my generator was using a lot of oil and blowing a lot of smoke...
When i pulled it down the exhaust chamber and muffler was just about fully clogged with carbon. After cleaning and reassembly it started using a varying amount of oil but still too much...
I then cleaned the fuel system, changed the oil to a single grade 30 and ran it flat out for four hours...
Nowadays it virtually doesnt use an oil, doesnt blow smoke and runs sweet and smooth...
If only i had of followed the manual in the first place...