Originally Posted by
DoyleAlley
There are three general uses for Sea Foam. One is as a fuel-system cleaner which would use the ratio you described. Second, is a carbon preventative. For two-stroke engines, I run Sea Foam at the rate of 1oz to 10 gallons of gas. That helps to prevent carbon from building up on the rings and valves. Third is as a shock treatment. That ratio is 1 can to 3/4 gallon of fuel - used in run/sit/run/sit sequence until the heavy smoking stops (burns carbon off of rings and valves).
It is also a stabilizer (see back of can). Also if you use it or anything else for cleaning the carbon out do not do it on a nice white driveway. It really makes a mess when done properly.
Fair Winds and Following Seas
Bill H. PTC USN Ret
Chesapeake, Va