discription of problem
discription of problem
I have recently acquired a 2000 22 ft pontoon with a 40 hp bigfoot. It runs great most of the time but does develop a miss at high rpm and/or with heavy loads (lots of passengers, pulling tow tubes). It comes and goes and is not always the same when it is present. Sometimes it is once every few seconds and other times it is three or four times a minute. When it misses there is a noticeable drop on the tach reading, 200-400 rpms, bounces down then right back up, I was first thinking/guessing loss of ignition power?? now guessing maybe plugged filter, going to change this anyway as a routine maintenance item.
Here is a little background and some other questions:
This weekend I discovered a water leak on the engine that was getting the ignition wet and causing a low speed miss, running really rough below 2500 rpm. I fixed the leak, installed new plugs and all was good there. I pulled the plugs tonight and they are a little toward a gray-white color, not coco brown like you want to see on auto plugs, does this rule apply for boats??? I am wondering if this might be an indicator of the Miss Problem?? Running a little lean?
While trouble shooting that I noticed a light coating of oil on the right side of the engine from the top down behind the carb stack. I am going to pull the air intake/filter assembly off and do some more investigation when I get more time/ambition. I see what I think is the crank case vent tube running behind there going between the valve cover and air box, might this be a source of the oil????
Any and all advice, ideas, comment or additional GUESSES are Encouraged and Welcome!!!
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