I have a Iseki rotavator about 15 years old. It goes like a train when on top form, I use a 25:1 mix but it smokes a lot and fouls the plug. I was told this is the mix reccomended by Iseki but that was in the days of 4 star petrol. Is there a any difference using unleaded?

Scubabeaver, September 2009

It's not the petrol that's changed - it's the oil. Modern synthetic 2 stroke oils are ok at 50:1, whatever the engine manufacturer recommended way back when.

I use 50:1 in my ancient flymo (recommended 16:1). It runs better, almost NO smoke, and doesn't foul plugs anymore.

phil_saunders(a)bigfoot.com

Phil Saunders, September 2009