imported post
You can find it at Napa, but a word of caution.
Add it right as you are filling your EMPTY gas tank. I say this because Seafoam seems to increase predetonation by about 1 pump's worth. (In other words, if you fill up with the cheap stuff, spring for the mid-grade.) This stuff is absolutley amazing. If you add it into your gas tank at 1 FLOz per US gallon (Sorry, I don't know the conversions) it will dissolve carbon knots on your valve stems, and generally flush goop out of the engine. You can also add it to the oil about 500 miles before you do an oil change, and it will dissolve any gunk that has been forming.Take notethough, if you do this, a glob of grease that has been sitting happily in a little nook may come loose and clog up an oil galley, or the pump intake screen.
Other ways to use it:
Bring the engine to operating tempurature, and then feed it full-strength into the fuel line. (A TEE fitting with a modle airplane fueling syrenge works well if you use a pair of hemostats to clamp off the main line at the right moment.) As soon as the engine begins to sputter, you kill it. Let it sit for 15 mins, and then fire it back up. (If you want to, you can draw the seafoam out of the fuel line with the syringe first, it'll make it start easier.) When it starts, there will be a huge cloud of white smoke as all of the seafoam and carbon is burned off. Best to do this out in the country, and not in your apartment complex parking lot.