From:Doug Miller
Subject:RE: gas oil mix Date:Wed Aug 20 21:38:52 2014
Response to:19802
Keep your oil mix the same what as you tuned the bike to. The new oils are better at lubricating and at burning so you might get away with a leaner mix of oil but you are taking the chance on YOURSELF.

With a modern 2 stroke oil for air cooled engines not outboards which are water cooled I tuned my 48 125 to a 32/1 mix by running it and "Chopping" the throttle. The plug has stayed clean and I get good power, there is a little oil around the exhaust clamp to the cylinder. But I don't want to go leaner since to go to far is catastrophic.

I have a 1953 ST. In 1953 the book said mix 25:1. Modern two cycles mix at 50:1. Is it the modern engine or the modern oil? What's the party line on what the mix should be?