I use oil in all my other engines, The only one I started not useing oil was the
YS as I was told it's just best if you run dry and store inverted because of the
regulator dia. and other parts like it, if you fly a lot, or if storing for long periods
use only full syn oil??? And I guess when I got the Saito I just did the same as
the YS.. But I see that the Saito does need the oil along with running it dry at the
end of the day.....

Jack I don't not believe it's just 4c's, all can have the problem.. Guess more so
in your area... Here it's a bit dry... So I gues less of that problem.. as I said
above the YS was the only one that went oilless... I had both my YS 63's open
and all looked great inside??? The Saito had a tint of that rust color.. So she's
getting oiled from now on... I believe running them dry is good to get most
the nitro out....