I use Sta-Bil on my boat because I leave old fuel in the boat. I think the Sta-Bil may do a better job of combining with water and helping stale fuel. The Sea Foam, I think, does a better job of cleaning the carbs, jets, etc. I was skeptical at first, but now will continue to use Sea Foam in my bike once or twice a year.
Fuel never gets stale in my bike. I probably will continue to use the Sta-Bil in my boat when it is sitting a lot.
