I mix MMO in my storage tank and draw it off for OPE, 2cycle mix, ATV, generators, etc... This stabilizes the fuel and reduces carbon build up. However, carbs used on these items and the environment they are used in often require a manual cleaning. "grit" is not cleaned by these chems. These carbs are simple, and much instruction on the web. If you have a FI ATV, it can be a bit more complicated.
But Seafoam, MMO, CRC, STP Multipurpose will do the general stuff when added to fuel. I caution the use of Carb sprays due the the "plastics" in these carbs. Especially 2 cycle carbs with plastic check valves and diaphrams. WD 40/soft tooth brush and needles/wire strands, work well for manual cleaining of small engine carbs.