Danny Wheeler
New member
ok I have a pontoon boat with a 1996 mercury bigfoot 50elpt4s serial# OG69Z866.
I am having a problem where the outboard will run for days at a time with no problems. Then all of the sudden after fishing for an hour or so when I start it up it starts spurting and will die. I can start it right back up and get it on plane and it seems to be running smooth all the way up to about 5500 rpms ( that is WOT for me with this prop) I purchased this boat about 2 years ago from a marina a few hours away. At the time they said they rebuilt the carbs. It ran good for a few weeks and then the problems started. They took it back and could not find any problems. Over the last 2 years I have taken it to three more marine mechanics and they have rebuilt the carbs, replaced all the fuel lines, fuel pump, coils, stator, fuel tank, filter, throttle and shift cables replaced, and rebuilt the lower end. I just got the outboard back last week and it has ran good for a few days then bam today I had to limp it back on the trailer. When I got home I started it and let it get warm. Set the throttle to full and did a compression test. I am getting #1 is at 180psi, #2 is at 179psi, #3 is at 179, and #4 is at 180 psi. According to the manual this should be just about perfect. What I did notice is the plugs were wet. It did not smell like gas, so I am assuming it is oil. It was not much but I was thinking they should be dry. I wiped with a rag and it was black. Every time I take it to the shop they tell me that they take it out to the lake and never have any problems. Is there any help you could give me. I was thinking that maybe it could be something to do with valve seats leaking or something like that. Thanks for your help
I am having a problem where the outboard will run for days at a time with no problems. Then all of the sudden after fishing for an hour or so when I start it up it starts spurting and will die. I can start it right back up and get it on plane and it seems to be running smooth all the way up to about 5500 rpms ( that is WOT for me with this prop) I purchased this boat about 2 years ago from a marina a few hours away. At the time they said they rebuilt the carbs. It ran good for a few weeks and then the problems started. They took it back and could not find any problems. Over the last 2 years I have taken it to three more marine mechanics and they have rebuilt the carbs, replaced all the fuel lines, fuel pump, coils, stator, fuel tank, filter, throttle and shift cables replaced, and rebuilt the lower end. I just got the outboard back last week and it has ran good for a few days then bam today I had to limp it back on the trailer. When I got home I started it and let it get warm. Set the throttle to full and did a compression test. I am getting #1 is at 180psi, #2 is at 179psi, #3 is at 179, and #4 is at 180 psi. According to the manual this should be just about perfect. What I did notice is the plugs were wet. It did not smell like gas, so I am assuming it is oil. It was not much but I was thinking they should be dry. I wiped with a rag and it was black. Every time I take it to the shop they tell me that they take it out to the lake and never have any problems. Is there any help you could give me. I was thinking that maybe it could be something to do with valve seats leaking or something like that. Thanks for your help