Mariner 40 Starts then Dies After a Short Run

[boatsmith]

When I first start my Mariner 40 (S/N OG402756, 1996 C40 ELPTO), on the trailer with the water ears on, I use the choke. It starts, I rev it with the neutral throttle lever and after 5 - 15 seconds, it dies. If I push in the choke button before it begins to stumble, it will recover for 5 seconds before I have to push the choke again. I have checked timing, checked synchronization of throttles, cleaned the carbs, replaced the fuel pump diaphram and used a new tank, fuel line and fresh fuel. A previous owner replaced the reed valves to correct a problem about 3 years ago. A previous owner also removed the oil injection system. This is a 4 cyl model with 2 carbs. Please help with any ideas of what to check out that may cause this. Is there any reason to believe it might perform better in the water at the dock?

 

[j_martin]

Re: Mariner 40 Starts then Dies After a Short Run

When I first start my Mariner 40 (S/N OG402756, 1996 C40 ELPTO), on the trailer with the water ears on, I use the choke. It starts, I rev it with the neutral throttle lever and after 5 - 15 seconds, it dies. If I push in the choke button before it begins to stumble, it will recover for 5 seconds before I have to push the choke again. I have checked timing, checked synchronization of throttles, cleaned the carbs, replaced the fuel pump diaphram and used a new tank, fuel line and fresh fuel. A previous owner replaced the reed valves to correct a problem about 3 years ago. A previous owner also removed the oil injection system. This is a 4 cyl model with 2 carbs. Please help with any ideas of what to check out that may cause this. Is there any reason to believe it might perform better in the water at the dock?

What happens to the primer bulb? What happens if you pump the primer bulb when it balks?

Could be an air leak, or plugged fuel line, or plugged gas tank vent. Answering the questions will help pin it down.

hope it helps
John

 

[boatsmith]

Re: Mariner 40 Starts then Dies After a Short Run

If I pump the primer bulb it makes no difference. The bulb will pump up very slightly after engine runs for a time but the engine doesn't respond. I am cleaning the carbureators and found that the bottom carb has a main jet stuck in the threads. This is the approx 1/8"-3/16" threaded brass jet that screws into the middle of the venturi from the bottom up. I cleaned that carb with spray Chem-Tool since I could not remove the jet and plastic venturi tube. It seems to have good spray through all ports. I'll replace it and try to run. If anyone has a used bottom carb in mint condition, I would like to buy it. The carb nos are
WMA 2
3330-830281C
13-3
0436
Engine S/N OG402756 - Mariner 40 HP, 4 cyl, 2 carbs, 1996
Be sure the jet threads are clean and jet screws out OK.