wcsd106
Petty Officer 2nd Class
- Joined
- Mar 27, 2010
- Messages
- 182
Mercury Classic 50 (45HP 2-Stroke Outboard)
S/N: A949635
Symptom: Bogs down under any load, will not plane boat
Good evening,
I am currently helping a buddy work on his Mercury Classic 50 outboard. A little over a month ago, he called me from the lake stating he had fuel gushing out of the front of his upper carburetor and it would not stay running. His outboard uses the carburetors with one separate external fuel pump instead of the individual fuel pumps. The following correction actions were taken:
This began to remind me of the time I sucked a twig into the throat of one of the carbs on my 200 Black Max outboard and chased what I believed to be a fuel problem until later finding out I had blown a switch box at the same time. So, having a few moments today, I performed tests on the outboard with the following results:
Compression:
Stator:
Trigger:
Since I'm seeing an improper resistance from the trigger leads when connected to the switch box, I'm inclined to suspect a failing switch box. This boat doesn't have a tachometer, but when I had it on the water this past Saturday, it didn't sound like it was getting to the correct RPM. It sounded as though it was getting somewhere in the neighborhood of 3500RPM. Much like my 200 did when it was having similar issues.
I'd appreciate any input from some of the Mercury gurus here. I've always had good luck in these forums, and am hoping that luck holds out.
Thanks.
S/N: A949635
Symptom: Bogs down under any load, will not plane boat
Good evening,
I am currently helping a buddy work on his Mercury Classic 50 outboard. A little over a month ago, he called me from the lake stating he had fuel gushing out of the front of his upper carburetor and it would not stay running. His outboard uses the carburetors with one separate external fuel pump instead of the individual fuel pumps. The following correction actions were taken:
- Disassembled Carburetors & Allowed To Soak in Carburetor Cleaner Dip
- Used Compressed Air to blow out all passages after soaking carburetors
- Visually inspected all jets to verify no blockages
- Replaced & set floats in both carburetors
- Reassembled Carburetors using new mercury OEM gasket set
- Tested float for proper function
- Installed carburetors
- Rebuilt external fuel pump using new Mercury OEM diaphragm kit
- Replaced all fuel lines from Carburetor to fuel pump, to engine fuel connector
- Replaced fuel lines from tank to outboard
This began to remind me of the time I sucked a twig into the throat of one of the carbs on my 200 Black Max outboard and chased what I believed to be a fuel problem until later finding out I had blown a switch box at the same time. So, having a few moments today, I performed tests on the outboard with the following results:
Compression:
- Cyl 1: 130lbs
- Cyl 2: 132lbs
- Cyl 3: 130lbs
- Cyl 4: 126lbs
Stator:
- Blue ~ Blu/Whi - Resistance Within Spec / DVA Measured Within Spec
- Red ~ Red/Whi - Resistance Within Spec / DVA Measured Within Spec
Trigger:
- Purple ~ White: Resistance & DVA Within Spec
- Brown ~ Whi/Blk: Resistance & DVA Within Spec
- Purple ~ Engine GND: Resistance when disconnected within spec (Open) Shows ~19k ohms when connected to switch box - DVA Within Spec
- White ~ Engine GND: Resistance when disconnected within spec (Open) Shows ~19k ohms when connected to switch box - DVA Within Spec
- Brown ~ Engine GND: Resistance when disconnected within spec (Open) Shows ~19k ohms when connected to switch box - DVA Within Spec
- White/Black ~ Engine GND: Resistance when disconnected within spec (Open) Shows ~19k ohms when connected to switch box - DVA Within Spec
- Primary / Secondary Resistance Within Spec
- Primary / Secondary Resistance Within Spec
- Primary / Secondary Resistance Within Spec
- Primary / Secondary Resistance Within Spec
Since I'm seeing an improper resistance from the trigger leads when connected to the switch box, I'm inclined to suspect a failing switch box. This boat doesn't have a tachometer, but when I had it on the water this past Saturday, it didn't sound like it was getting to the correct RPM. It sounded as though it was getting somewhere in the neighborhood of 3500RPM. Much like my 200 did when it was having similar issues.
I'd appreciate any input from some of the Mercury gurus here. I've always had good luck in these forums, and am hoping that luck holds out.
Thanks.