I have never put it in snowmobile oil however contrary to all the posts I use it frequently in my stand up jetskis when I sink them or fill the motor compartment up with water. In fact I have fogged the motor with it, dumped straight down the plug holes & straight into the carbs thru the reeds and into the case. It is an excellent decarbonizer, the trick on jet ski's is to get it started heat up the motor and get it hot and running immediately to eliminate the water. I have had the cases filled with water and the motor hydro-locked. It has saved my bacon a couple of times a year, both motors are modded out, big carbs, pipes, high comp heads, and has never once caused me problems. If you want to clean the carbon out , if that is what your after , dump it in the carbs ( outside your parents garage) and let it do it's thing. keep revving it until the SF is burned up . It will smoke the heck out of your neighborhood. It will peel the carbon right off the pistons, plugs everything. Just get your motor hot and flush out the SF then keep running your gas & oil through it. I'm not standing behind or promoting their product but I have never had a bad experience with it. this is not intended to offend others members opinions.