Mercury Part #: 8M6002988 & 804533

8M6002988:
This diaphragm fits both the air and fuel regulator on all of the Optimax 3.0L Model Engines (200 - 300 HP).

Additionally,it is the same diaphragm used for the fuel diaphragm on the Optimax 2.5L Model Engines (135 - 175 HP). This

diaphragm issed 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 siderail for the 2.5L engines. The Air/Fuel diaphragm for sale is not the tracker diaphragm that is installed in the

starboard fuelrail on either the 2.5L or 3.0L Optimax Engine. This diaphragm is the flat top.

804533:
The tracker diaphragm is identified by a short knob at the top of the part. The tracker diaphragm that is installed in the

starboard fuel rail on either the 2.5L (135 - 175 HP) or 3.0L (200-300 HP) Optimax Engines.