seafoam ain't worth a flip, most folks in the marine industry do not use it, they may sell it to make a buck, but they won't use it. I use marine stabil and yamaha ring-free in everything I own and have never once had to pull off a carb. When I went to school at yamaha years ago, they had two identical motors sitting on a table that were cut in half so that you could view the short block as it was put together. One motor never had anything ran through it, the other had yamalube ring free ran though it for its entire life. Both motors had 20,000 hours on them. The ring free motor looked brand spanking new, even the exhaust valves. The other motor was carboned up bad. That told me what I needed to know.