Thunderbolt 40 with Blue Band

[hojon64]

I bought the Check Valve Kit 218M0084275 and noticed that the check valves have two different colors. One has a clear diaphragm (center) and the other is black diaphragm (center). Both of the ones in my fuel pump are clear so I was wondering with one of the two in this kit is for the intake side of the pump and which one os for the output of the pump. My motor is a thunderbolt 40 hp with the Blue band from around the early 80's.

 

[Quicksilver]

It's not a Thunderbolt it's a Mercury - look for a serial Nr. The serial number was on a plate riveted to the port side of the swivel bracket or between the thumbscrews.