you have to determine if the previous owner was mixing the fuel and oil @ 32:1 or still using the oil injection system that you mention the tank under the seat,
you have to be doing one or the other, but not both.
his mention of 32;1 leads to believe he was premixing, not injecting it, as there is no "32:1 oil"
that is a reference to the ratio any oil can be mixed at, 4 ounces of oil per 1 gallon of fuel.
be sure to figure out...premix or injection ? before running that engine again.
and be sure to get the correct oil for either.
maxima makes 2 different blends of their Super-M, for mixing or injection.
the factory yamalube also makes a good injection type.