I bought a 1985 Mazda RX7 GSL from a friend, it could not pass smog (California thing). The car start and idle ok, but when you rev the engine it start sputtering at 5500 rpm. Timing is set at 0 degrees tdc on the leading side and 20 degrees atdc on the trailing side. The carburetor was overhauled 4 years ago per the original owner. The fuel filter was replaced and fuel has a good flow to the carburetor. Both igniter works fine, just for kicks, I replaced both with a new one. It sputters as the secondaries open up. All four jets has a nice spray on them. just fyi, car has new spark plugs and wires, air and fuel filter. emptied the gas tank and poured seafoam then filled the tank with premium gas. Your help is much appreciated. Thanks in advance.

 

You might want to get rid of that premium and put in 87 octane. I remember reading that premium doesn't burn all the way like 87 does. I know that probably won't help with your secondary problem, but just remember to use 87 octane next time.

 

I was hoping that the premium gas would help...but it still runs the same

 

When doing a seafoam run it needs to be driven for a while to burn it out.

Like 2-3+ hours. Also you don't need to be getting that high rpm's during the cleaning process with that stuff in your fuel. It's not something you want to race with. Unless you want the person to get lost in smoke trail.

 

Did you replace the cap and rotor? There should only be a 10degree split on the trailing IIRC

 

both rotor and cap were replaced, I removed the spark plug yesterday and found carbon deposit on them so I replaced all four.