hi there call me thick but how much oil to 5 litres of petrol do i need manual says 80~1 but was going to run 70~1 using full syn oil had a go at working it out (72 mili litres )wrong i think any info would be gratefull

You'll have no problems at 80:1, which is 62.5 ml to 5 litres of fuel. Try and get the best fuel you can, I used to run optimax (v power now) which seemed to help with reducing pinking.

For ratio's see here

http://www.beta.id.au/2%20Stroke%20Fuel-Oil%20Ratios.htm

cheers thanks for reply