I will have to agree to disagree..The old A&M gassers were loose as a goose right from the factory..Seems like the recommended ratio was synthetic at 100-1..
From the Zenoah G26PU (aircraft_ and PUM (marine) factory specs....Standard clearance between piston and cylinder is .00118 to .002...Considered worn at .005...Recommended oil ratio is 25-40 to 1...
So a piston/cylinder fit of .0011 is OK with 25-1 oil...Kinda blows the theory about oil ratio for closer clearances...NO gasser will run for very long with a piston/cylinder fit of less than .001, so I highly doubt the "precision fit" of a Toro is any closer than that....
Clarence Lee once said that oil helps carry heat away...I will not dispute that[>:]