I am using the OS#F in my saito 80 in my F40. Starts first flip all the time, awesome reliability, never have to touch it. Have put about 10 litres of 10% and 15% fuel through it on the same plug and the only dead stick ive had was when i got carried away and ran out of fuel.I had loads of hassels with the saito plugs, as the motor had not run in about 5 years, and I agree with the posts above, that the 72 will only be better with the OS #F plug.