Mercury Classic 50 45 Carb Swap

[bojango541]

Hello,

I have a mid-late 1980s 45 HP Mariner/Merc that has carburetor issues. I bought a parts motor that is a little older that has carbs that were just rebuilt. The motor on my boat now has the big square fuel pump. The carbs on the parts motor have the fuel pumps built into each carburetor. I was told by a mechanic I can just remove the square fuel pump and block that off, then bolt on the other set of carbs. My question is, Not sure exactly what needs to be blocked off, and I feel like I have to many extra fuel lines now that I've eliminated the stand-alone fuel pump. Really would be helpful for some input on the topic. I took a couple of pictures, and can get more if needed.


http://i146.photobucket.com/albums/r260/bojango145/20130925_170010_zpse667fcdc.jpg

http://i146.photobucket.com/albums/r260/bojango145/20130925_170000_zps1320d9d0.jpg

http://i146.photobucket.com/albums/r260/bojango145/20130925_170057_zpsc9bdf6b5.jpg



The last picture, the is a line going from the fuel pump I am removing to the bottom of the block/crankcase. Does this need to be blocked off or still used?

 

[achris]

Re: Mercury Classic 50 45 Carb Swap

To remove the pump from the block you need to block off two points. One is the hose running from a port on the block to the fuel pump, and the other is the hole left in the block where the pump was mounted. Both these holes are for pressure pulses to run the pump. The pumps on the older carbs get their pulses from ports on the inlet manifold, which you need to check and make sure they are there...

If the pulse holes are in the right place on the manifold for the older carbs mount to, then just plug the old pump hose, and make a plate to bolt in place of the pump to close the other pulse hole...

Chris.....

 

[bojango541]

Re: Mercury Classic 50 45 Carb Swap

excellent. Thank you

 

[bojango541]

Re: Mercury Classic 50 45 Carb Swap

Do you think I could just cover it with some sort of epoxy?

 

[achris]

Re: Mercury Classic 50 45 Carb Swap

Cover what with epoxy, the pulse ports in the block? I wouldn't....