I just rececently aquired a 1981 Mazda rx7, and i went down to the gas station, got some premium fuel, put it in the car, and fired it up, at first it was puffin out blue smoke, then once i warmed up it kinda went away, but now its just black smoke, and it looks like its burning too much gas. Suggestions?

Its a 12A, 1981.

 

change to 87 octane fuel. Do not use any higher than that.

 

Alright Will do,

THanks.