Hi folks: Some time ago I mentioned a good way to keep your 2 cycle gas engines running good is to rev them up and throw the choke on. This floods the engie out and protects all parts inside with exta oil. Yo do this on very last flight of the day or any engine you want to lube up. It keeps the seals soft also. Carbon build-up to my supprize was not a problem. It seems the carbon is keep soft and blows out on start up. I have been doing this for twenty years on my engines. Works great. The guys that have tried it agree. This is not a way too shut down engine...except for the last run of the day. Although snomobile engines several hours later will start right up without choke. My Snomobile that I did this with...was the fastest stock one in my area. Also I have a reed valve 4.2 chainsaw that runs perfect to this day. Never had ot do anything. Seals stay like they should...pliable. Try it....see for yourself. Thanks Capt,n