Mercury Tracker 40 Powerhead Removal

Our 2002 Mercury Tracker 40 two-stroke had issues we needed to resolve, and doing so began with a couple of quick diagnostics to see what was going on inside the motor. 

Watch the video above and follow the steps below to learn how to remove the powerhead from a Mercury Tracker 40HP two-stroke outboard engine. 

Before we get to the steps involved in the powerhead removal of our 40HP Mercury outboard, let’s talk about why we had to remove it in the first place. For starters, we took a look at the spark plugs, and one of them had a lot of residue on it. 

Since we already had the plugs out, we looked inside the cylinder with a borescope to see what else was going on. What we saw wasn’t pretty. A needle bearing had come loose, bounced around inside the cylinder and scarred the piston face before getting caught and digging a trench in the cylinder wall. 

This sort of damage requires significant work, but at this stage we couldn’t even tell what needed to be done. Is the crankshaft usable? Are the connecting rods bent? There’s no way of telling until we break the motor down and get a closer look, which is why the powerhead needed to be removed.

How to Remove the Powerhead from a Mercury Tracker 40 2-Stroke

Step 1. Remove the cowling underneath the powerhead, which is held in place by one 8mm bolt that goes all the way through to the other side. 

Step 2. Disconnect the oil reservoir. Use wire cutters to cut the zip tie that secures the hose, then use needlenose pliers to get the hose off the nipple by twisting it a little.

Step 3. Feed the line up, and secure it so that the end of the hose stays above the level of the reservoir to keep any oil from draining out. 

Step 4. Remove the two bolts that hold the reservoir in place, then lift the reservoir off and set it aside, making sure to keep the line above the level of the oil. 

Step 5. Disconnect the telltale, which is held in place by a zip tie.  

NOTE: Be careful as you remove it, since it’s a plastic fitting that’ll break if you push it too hard.

Step 6. Disconnect the ground wire connected to the motor that’s held in place by an 8mm bolt. 

PRO TIP: Put the bolt back in place after disconnecting the wire so you don’t lose it.

Step 7. Disconnect the trim relay wires. 

PRO TIP: There are a few wires that need to be disconnected here, and they’re all color-coded, so it’s a good idea to take a picture of them for when it’s time to reconnect them.

Step 8. Disconnect the last ground wire.

Step 9. Remove the three main bolts underneath both sides of the engine to release it. 

NOTE: The next step involves removing the motor, which will probably resist a little as you lift it.

Step 10. Place a 10mm wrench at the base of the motor and use it as a surface to rest a pry bar on, then lift the motor away from the rest of the outboard and you’re done.

NOTE: Don’t pry against the bottom piece of cowling, since it’s plastic and it’ll break.

Want to see more work done on a Mercury Tracker 40 two-stroke outboard? Check out the playlist below to see the full list of maintenance and repairs.