Hi
I have a year 2000 Mariner 40 4 stroke on my little open sport fisher boat . I have just returned from my annual 2 week vacation during which it developed a serious power problem. It seemed to gradually get worse over the period of a couple of outings to the point it now stalls out when you try to accelerate past 2000rpm under load. I think I have checked all the obvious things and the first thing I noticed was that when I remove individual plug leads on cyl 1 and 2 it stalls even at idle but when I remove cyl 3 lead there is no change to the engine note. Assuming it was going to be something simple like a lack of spark I checked to see and I am still getting a strong spark on cyl 3. I changed over plugs and then coils but still the same. Having decided it wasn't electrical I took off the carbs and cleaned out and checked carb 3 and everything seems fine. I am starting to think it might be something more serious and will be checking compressions as soon as I can.
Could I still be missing something simple or do you think I am looking at a more serious problem.
Thanks for any help or advice anyone can give.
I have a year 2000 Mariner 40 4 stroke on my little open sport fisher boat . I have just returned from my annual 2 week vacation during which it developed a serious power problem. It seemed to gradually get worse over the period of a couple of outings to the point it now stalls out when you try to accelerate past 2000rpm under load. I think I have checked all the obvious things and the first thing I noticed was that when I remove individual plug leads on cyl 1 and 2 it stalls even at idle but when I remove cyl 3 lead there is no change to the engine note. Assuming it was going to be something simple like a lack of spark I checked to see and I am still getting a strong spark on cyl 3. I changed over plugs and then coils but still the same. Having decided it wasn't electrical I took off the carbs and cleaned out and checked carb 3 and everything seems fine. I am starting to think it might be something more serious and will be checking compressions as soon as I can.
Could I still be missing something simple or do you think I am looking at a more serious problem.
Thanks for any help or advice anyone can give.