Do Mazda RX-7 FD owners regret removing the oil metering pump?

If you are considering an OMP delete on a rotary engine, there are several operational consequences to keep in mind that might influence that decision:

• Premixing is Required: Without the OMP, you must manually mix 2-stroke oil into your gasoline for engine lubrication. The standard ratio is roughly 1 ounce of 2-stroke oil for every gallon of gas, or about 16 ounces per full tank ¹.
• Emissions and Odor: Running premix will alter your exhaust, making it smell similar to a lawnmower. This can make passing strict emissions testing much more difficult ¹.
• Blockoff Plate Necessity: If you remove the pump, you must install a dedicated blockoff plate. Without it, the engine will spew oil everywhere while running ¹.
• Hardware Specifics: For reference, the factory FD oil metering pump utilizes two output holes, which differs from older FC models that feature four output holes ².

Because of the continuous requirement to measure and add oil at every fuel stop, as well as the resulting exhaust smell, some owners ultimately prefer to keep or revert the system back to stock ¹.