Logo
FULL SITE MENU

2002 Mercury 125hp stalls under load

T

Texdan25

New member
My 2002 Mercury 125 runs fine in the driveway with muffs or at the ramp on the trailer but when put into gear the motor dies. I'm guessing it might be a carb problem? I had some old gas in it and although treated for ethanol I drained the tank and it was in pretty bad shape. Would running Sea Foam through it clean the carbs good enough to fix this problem, or use the Sea Foam spray into the carbs while running? Have also heard of the Mercury Tune up? Any other ideas? Thanks.
 
Per Faztbullet: "Get a factory manual and test ignition then rebuild carbs with new kits."

While doing that, inspect the carbs for little black specks under the top plate and in the bowl, and ensure you solvent clean the whole disassembled carb, run a wire in all holes you can find, and lots of 100 PSI air pressure to blow things out....ensuring the high speed jet...in the bottom of the bowl, is clean. If you find any black specks, install new fuel lines in the engine and if doing that, might as well install a new tank to engine line and bulb.

Replace the engine fuel filters both the large one and the small one just behind the oil tank on the aft side, midway up. Cut them open and if you see any black specks and tan chips, you are solidifying what I said above...hoses are shot and dirty. Then check your linkage plastic parts for wear and if any slop or broken pieces get new. Finally do a link and sync per the manual.

Adding Sea Foam to the fuel was a habit of mine and I was convinced it was worth the money and time, there and in other engines I have around the farm. I have been running 2002 3 and 4 cylinder engines since 2004, currently running the 115, and the above comments are some of my maintenance history. Course I have a couple more personal tweaks on the 115 but that's another story.​
 
Last edited:
Texasmark said:
Per Faztbullet: "Get a factory manual and test ignition then rebuild carbs with new kits."

While doing that, inspect the carbs for little black specks under the top plate and in the bowl, and ensure you solvent clean the whole disassembled carb, run a wire in all holes you can find, and lots of 100 PSI air pressure to blow things out....ensuring the high speed jet...in the bottom of the bowl, is clean. If you find any black specks, install new fuel lines in the engine and if doing that, might as well install a new tank to engine line and bulb.

Replace the engine fuel filters both the large one and the small one just behind the oil tank on the aft side, midway up. Cut them open and if you see any black specks and tan chips, you are solidifying what I said above...hoses are shot and dirty. Then check your linkage plastic parts for wear and if any slop or broken pieces get new. Finally do a link and sync per the manual.

Adding Sea Foam to the fuel was a habit of mine and I was convinced it was worth the money and time, there and in other engines I have around the farm. I have been running 2002 3 and 4 cylinder engines since 2004, currently running the 115, and the above comments are some of my maintenance history. Course I have a couple more personal tweaks on the 115 but that's another story.​
Click to expand...


Thanks for the tips. I am not much of a mechanic and especially not a 'carb' guy. Was just hoping someone might have a comment/experience with running a heavy dose of Sea Foam to try and clean carb without removing/disassembly. Lots of youtube videos on that. Guess it doesn't hurt to try before taking it to the shop?
 
Texdan25 said:
Thanks for the tips. I am not much of a mechanic and especially not a 'carb' guy. Was just hoping someone might have a comment/experience with running a heavy dose of Sea Foam to try and clean carb without removing/disassembly. Lots of youtube videos on that. Guess it doesn't hurt to try before taking it to the shop?
Click to expand...
No such thing as mechanic in a can! Take it to a shop that has experience with the 2+2 motors.
 
Back
Top