mariner 55 Fuel system

[rwima]

welcome everybody
I want to understand what is the use of this hole in the fuel pump


in the crank case unti there is the same hole
thanks all

 

[faztbullet]

That the passage the crankcase pulse pressures use to move diaphragm in pump.

 

[rwima]

That the passage the crankcase pulse pressures use to move diaphragm in pump.

Thank you, there's a place for the pulse from the top. Does this pump need two pulses?

 

[racerone]

Post more pictures of the pump and the block where it mounts.------These pumps are very reliable.----What is your motor doing / not doing that leads you to taking fuel pump apart ?

 

[rwima]

Post more pictures of the pump and the block where it mounts.------These pumps are very reliable.----What is your motor doing / not doing that leads you to taking fuel pump apart ?

Thank you for your response
Mariner 55 3 cylinders 2 stroke
On very high speed the fuel pump not working And I must manually pump the fuel so that the engine does not stop
The fuel pump is new
I'm asking because the same hole in the carank case look lilke bloked
Is it normal for it to be closed and not emit any air to the pump?
The pulse that comes from the top is working , but the pulse below the fuel pump does not