Fit Mercury Rail Air/fuel Regulator & Tracker Diaphragm 8m6002988 &

This diaphragm fits both the air and fuel regulator on all of the Optimax 3.0L Model Engines (200 - 300 HP). The previous models were either green or brown in color. This diaphragm is used in either regulator (fuel or air) on the port side fuel rail for the 3.0L engines, and for the fuel regulator in the port side rail for the 2.5L engines.