Mercury Tracker 40 2-Stroke Fuel Pump Rebuild 

Rebuilding the fuel pump on a Mercury Tracker 40 doesn’t take much. All you need are some basic tools (ratchet, extensions, screwdriver) to disassemble and reassemble it. 

As far as parts go, Mercury has a fuel pump diaphragm kit that has everything you need to do this project, which is part of our complete outboard engine rebuild. 

Mercury 40 two-stroke outboard fuel pump rebuild diaphragm kit

Watch the video above and follow the steps below to rebuild the fuel pump on a Mercury 40HP two-stroke outboard.

Buy Mercury 40 fuel pump rebuild kit

Buy OEM Mercury 40 outboard parts

NOTE: We’re rebuilding this outboard motor from the crankshaft up. You don’t need to take your entire motor apart to get to the fuel pump. 

Mercury 40 two-stroke outboard fuel pump

Step 1. Disconnect the three fuel lines connected to the fuel pump, then release the bolts that hold the fuel pump in place and pull the pump off the engine.

Mercury 40 two-stroke outboard fuel pump rebuild

PRO TIP: Before you disassemble the fuel pump, use a marker to help you figure out what orientation it needs to be in when it’s remounted.

Mercury 40HP two-stroke outboard fuel pump rebuild

Step 2. Remove the bolts from the fuel pump assembly, then use a flat-blade screwdriver to pry it apart.

Mercury 40 Tracker two-stroke outboard fuel pump rebuild

Mercury 40HP Tracker two-stroke outboard fuel pump rebuild

Step 3. Remove the components that make up the fuel pump assembly, including all gaskets and diaphragms.

Mercury 40HP Tracker outboard fuel pump rebuild

Mercury 40 Tracker outboard fuel pump rebuild

NOTE: Use our Mercury 40 exploded parts diagrams for reference of how things came apart and back together again.

Mercury 40 Tracker outboard engine fuel pump rebuild

Step 4. Remove the check valves. 

Mercury 40 Tracker outboard motor fuel pump rebuild

NOTE: The Mercury 40 outboard we worked on is a later model unit which has plastic or nylon check valves. If your outboard is an older model, you may have to drill out for a larger pin set for the little retaining clip to go back in.

Step 5. Pop the springs and caps out by pushing in on the center pin to release them.

Mercury 40 Tracker fuel pump rebuild

Mercury 40HP Tracker fuel pump rebuild

Step 6. Install the new check valves and press them in. 

Mercury 40HP Tracker fuel pump rebuild

NOTE: According to the service manual, when you push the check valve in, it'll stop and then you have to break off the end. However, one of ours (the one on the left pictured below) went in like it was supposed to, and flowered out the other end to where it holds it in place, so there was nothing to break off. 

Mercury 40HP Tracker two-stroke fuel pump rebuild

Step 7. Install the new spring and the plastic seat for both sides of the fuel pump.

Mercury 40HP two-stroke fuel pump rebuild

NOTE: One side has a smaller plastic seat and spring. 

Mercury two-stroke outboard fuel pump rebuild

Step 8. Reassemble the fuel pump assembly in the same order it was before you took it apart (diaphragms, rear plate, mounting bolts, etc.).

Mercury outboard fuel pump rebuild

Mercury outboard engine fuel pump rebuild

Mercury outboard motor fuel pump rebuild

Mercury 40 outboard motor fuel pump repair

Mercury 40 outboard motor fuel pump assembly

Step 9. Install the top outer gasket over the fuel pump assembly, then mount the fuel pump back onto the engine block. Next, tighten the bolts by going around a couple of times to compress all those gaskets down to where they seal up.

Mercury Tracker 40 outboard fuel pump remount

Mercury 40HP outboard fuel pump remount

Step 10. Reconnect the three fuel lines back up to the fuel pump and you’re done. 

Watch the playlist above for our complete series on Mercury 40 Tracker two-stroke outboard repairs.

 
DIAPHRAGM KIT
Mercury

DIAPHRAGM KIT

Qty.
FUEL PUMP KIT
Mercury

FUEL PUMP KIT

Qty.

 

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