This really seems to work. I read it on a can of Klotz oil part# 300. It not only works with Klotz oil but with every brand I have used. On the can it said the engine should be killed (on last run) by choking out the carb rahter than by ignition switch. I went one further...I reved the engine full throttle and choked it out at full rpm. Doing so really pulled in a lot of extra fuel and oil. I noticed the engine on my chainsaw or snomobile would start the next day without even choking. That was great!!! I thought maybe carbon would build up faster by doing this. NOT SO!!! I think the extra oil and whatever it may contain, would lossen up any deposits when engine was setting untill next start-up. I never had to de-carbonize any engine. My spark plugs seemed to last forever. I did take the plug out and soak it in a jar of laqurer thinner or carb cleaner, using another plug in engine while other plug was soaking. A blast of compressed air would clean sparkplug after soaking. My engines always ran great...rings stayed free...seals always stayed like new. I tell you...that extra lube in that engine after killing it with choke does wonders. I have been doing it for over 20 some years on all types of gas 2 stroke engines. Now about the best oil...I don,t know...but it is far more important to have the hi-speed needle set right. Having the correct carb settings is more important than what 2 stroke oil used. I will say Klotz oil says on can....will not burn in engine...thus leaving no deposites. About my engines...I have had guys say they would rather buy a used engine of mine than to buy a new one. Hope this helps someone. Thanks Capt,n