Re: 100:1 Mix
What a great discussion. Just some thoughts; 'oil makes it run hotter'...well, maybe to a point; I have never done the experimenting described. But just as a caution, try running a 2-cycle with no oil (hey, it was an accident!) and I promise you, it was not running cool when I finally shut it down. Compression was then so bad, it would only start and run if I put 10:1 mix in (trashed rings, cracked). Just a high oil ratio can compensate for bad rings to some extent...e.g. the 2 cans of STP I add to the 40W in my old Jeep until I get the ambition to overhaul...4cycle, but same issue; extra oil in the game keeps gas from blowing by the rings...
I wonder if the mixed results with the 100:1 has a bit to do with the inconsistency of the Chinese engines? The problems 2door described also could be classic crank bearing tightness/lack of lube. At 100:1, there isn't that much lube left to find its way onto the crank. A motor with better (or even sloppier) bearing clearance might not be affected.
After looking at the Opti site, looks like part of their gig is similar to the idea behind Slick50 and similar engine treatments. That is, a formula that at least theoretically creates or catalyzes a metal distribution or redistribution to fill in gaps and remove peaks. I still haven't decided whether the Slick50 I have used did any good or not. Anyone ever try it on a China bike engine?
And the SeaFoam carbon remover is a higher-cost trick several old wrenches I knew used to do with plain kerosene: if a head is carboned up, get engine warn, run it at high idle, pour kerosene slowly into the carb until the engine dies. Let it sit/soak overnight. Start next day and run; watch black and blue crap spew out the back, repeat as desired. It really does work!
Sounds like no 2 China engines are exactly the same, so folks should use what works and is comfortable for them.
I sure enjoy being able to soak up all the knowledge, ideas, and experiences from this group!