I have a 1989 Mercury Blackmax XR4 150hp 2 stroke carb motor. There was previous substance added in the gas tank for fuel treatment from the previous owner.
Can I add B12 to the tank without issues?
How often can I add B12?
If I add to tank then let it sit, how long can it sit before it is no longer Effective?
Yes, any of our B-12 Chemtool family of gasoline fuel additives should be compatible with the previous fuel treatment. The suggested frequency of use depends on the product; part #0116 in the metal can, for instance, is recommended every third tank but is actually safe for use as often as desired. As for longevity, these additives will retain their effectiveness for at least a year in sealed tanks. In open tanks, their efficacy depends on numerous factors, including fuel system configuration, temperature, humidity, type of gas, and fuel level.