Mercruiser 3.0 LX Mechanical Fuel Pump. I am replacing with a new one is this normal?

[Bayliner3.0]

I have a 3.0 LX Mercruiser motor and it has a filter down, cam actuated mechanical fuel pump. I ordered a new one and tried pressing down the rocker arm on the pump (arm that the cam shaft moves with the spring on it) and it does not move.
I did not try too hard, but I am wondering is this normal? I assume it might need vacuum or pressure to move, but I do not want to install it and damage my engine. I have the manual for my engine, seems straight forward in install but any tips or advice is welcome too.
Please help. Thanks.

 

[Scott06]

I have a 3.0 LX Mercruiser motor and it has a filter down, cam actuated mechanical fuel pump. I ordered a new one and tried pressing down the rocker arm on the pump (arm that the cam shaft moves with the spring on it) and it does not move.
I did not try too hard, but I am wondering is this normal? I assume it might need vacuum or pressure to move, but I do not want to install it and damage my engine. I have the manual for my engine, seems straight forward in install but any tips or advice is welcome too.
Please help. Thanks.

Clamp it in a vice. It will be stiff but should move. Doesnt need vacuum or pressure but there may be plugs in the inlet and outlet that need to be removed . If it doesn’t move return the pump.

 

[Bayliner3.0]

Clamp it in a vice. It will be stiff but should move. Doesnt need vacuum or pressure but there may be plugs in the inlet and outlet that need to be removed . If it doesn’t move return the pump.

Thank you sir! I just pushed a little more and it moves. Pretty stiff, but I guess it is nothing to the engines torque.
Any chance you know a torque spec for these? I have the manuals but it only references 25 ft lb to bolt to water pick up pump.. Mine bolts to the block directly. I do not want to crack the block in anyway.

 

[stresspoint]

to fit a new fuel pump > move the motor to TDC compression #1 cylinder " or " poke a screw drive and find the part of the pump lobe that is highest as the pump lever pushes from the bottom of the lobe if that makes any sense in text ' .
when you put the pump in the 2 bolts should go in most of the way in finger tight , if not you rotate the motor till you can .
if you cant get them in finger tight there is an issue with the pump..

too test the pump put your finger on the outlet and crank the motor , you should fell pressure , if no pressure the fuel pump will not pump fuel. either lobe is worn out , pump lever is bent or pump is faulty.

 

[Scott06]

Thank you sir! I just pushed a little more and it moves. Pretty stiff, but I guess it is nothing to the engines torque.
Any chance you know a torque spec for these? I have the manuals but it only references 25 ft lb to bolt to water pick up pump.. Mine bolts to the block directly. I do not want to crack the block in anyway.

no good and snug with a calibrated elbow....

 

[Lou C]

those springs are very stiff
the bump on the camshaft can push it down but you likely can't lol
easier than dealing with the pushrod on the V6s which don't have the extra hole in the block like the V8 to hold it still temporarily with a longer bolt!

 

[stresspoint]

those springs are very stiff
the bump on the camshaft can push it down but you likely can't lol
easier than dealing with the pushrod on the V6s which don't have the extra hole in the block like the V8 to hold it still temporarily with a longer bolt!

hey Lou .a trick i learned long ago to stop the push rod falling down as you fit the pump . a very small dob of aviation sealant stops the thing sliding out on you.

Op , chances are you wont be able to move that lever much and trying could possibly damage/ bend the lever off to one side.

 

[Lou C]

hey Lou .a trick i learned long ago to stop the push rod falling down as you fit the pump . a very small dob of aviation sealant stops the thing sliding out on you.

Op , chances are you wont be able to move that lever much and trying could possibly damage/ bend the lever off to one side.

Yep I used a dab or 2 of Evinrude triple guard grease (what we call blue snot lol) which also works. I do like the old school mechanical pump, the last one I replaced was 30 years old, and no wiring/terminal headaches, they just work, and work!

 

[Scott Danforth]

and no wiring/terminal headaches, they just work, and work!

and are half the cost of the electric