Fellas,
I feel compelled to share my thoughts & practices on motor oil, gasoline and their additives:
MOTOR OIL:
I use straight 30W TRAVELER'S motor oil from the local Tractor Supply Company (TSC) store.
I change it twice a mowing season = every 25-30 hrs of run time. I have an hour meter on my 129 Cub and will soon put one on my 127 Cub.
I've tried the ceramic additive, I've tried the Sea Foam stuff. Neither impressed me as doing anything for my K301 Kohlers.
For about two years I've been using it in my 4-cyl Ranger [now with 302K miles] and it's consumption rate has also been reduced. So, during my last Kohler oil change, I added 5oz. of LUCAS Heavy Duty Oil Stabilizer and topped it off with the TSC 30W motor oil. That engine used to smoke some when worked hard, and it doesn't any longer. After two/three hours of use, I would have to add oil, as it would be down the dipstick 1/4" to 1/2" inch, now the oil consumption is much less than half that rate! I'M SOLD ON LUCAS!
GASOLINE:
I use mid-grade, quality, name-brand gasoline because I believe it lasts longer in the can and in the fuel tank and doesn't varnish up the fuel system like regular grade, no-name gas does. I use mid-grade fuel with MMO (mixed according to the MMO ratio) in all my air-cooled, 4-cycle engines. During the off-season, I don't drain the fuel tanks, rather I make sure that I start and run each engine at least once a month for at least 10 minutes.
I used to drain the fuel systems each Fall, but then I'd have dried out & leaking gaskets/seals in the Spring. So, I have determined it to be better to leave some fuel (1/2 tank full) in the systems, and just run the engine periodically to burn some of the soon-to-be-stall gasoline. For the first Spring outing of more than 1 hour run time, I fill the tank, burn it nearly dry, change my inline fuel filter, and refill the tank.
I plan to remove the two Kohler cylinder heads after 100 hrs just to see what they look like. I expect them to be very clean and nearly carbon-less.
For what's it's worth, the above practice has served me well!
Ryan Wilke
P.S.
I don't believe gasoline with 10% ethanol 'stays good' nearly as long as 100% gasoline (which is no longer available near me) once did.
If the gasoline storage can or fuel tank is vented to the atmosphere, it WILL "go bad" in just a few weeks.