---

Not to hijack the thread here, but MW mentioned Carbon Guard, which I use also. Just had my carbs rebuilt, and the mechanic at the shop advised that Carbon Guard use isn't necesary for pre-mix if you are using Evinrude/Johnson "XD30" oil. Supposedly this oil has Carbon Guard in it, and the previous "XD20" didn't, although I've not yet confirmed that.

Back to Sea Foam, I'm a little confused also as its many supporters have described it doing a lot of good things, being used at least 3 different ways. I've not read anywhere that inhibiting carbon buildup is one of those functions, which I believe is Bombardier's "Carbon Guard" function. I've read of Seafoam use these ways:
Spray into carb throats: carburetor cleaning/varnich remover and engine decarboning
Spray directly into top of cylinders and soak: piston/cylinder/ring decarboning
Fuel Treatment: decarboning and maybe also carburetor cleaning? Either strong concentration for cleaning or more diluted for regular use.

Seems like all the OEMs have their own assortment of recommended specific somewhat comparable concoctions. For Evinrude/Johnson, aside from Carbon Guard, their other product is Engine Tuner (decarb via spray into carbs and/or soak in cylinders). They also have "2+2" fuel conditioner, which I assume is similar to Stabil. I am unaware of a Bombardier product for in-place carburetor cleaning.

I also wonder as others have how well or not multi-part cocktails of these additives work together in a given tank.