OK , this inline 6 with serial number 509****, was going great guns earlier in the summer, until July 4th that was. During the middle of pulling kids in a tube it was as if a switch had been turned. The engine sputtered and coughed back to shore. We're using fresh mid-octane gas of course.
Since then I have torn apart the carbs (not especially gummed up,) soaked them in cleaner, installed new gaskets, new needles and seats. Checked to float levers to make sure they measure correctly. The fuel pump was overhauled last fall and the diaghragm is still fine (no leaks, dry on the back side).
Compressions are 115, 111, 115, 118, 112, 113. New Champion plugs were put in this spring and I have month old plug wiires in place. I followed this up with most of a can of Sea Foam thru the fuel line. It was some pretty ghastly smoke there for a while though.
I took it over to the local lake and while bothered only by some mild sputtering trying get a hole shut with the overhauled carburetors, things worked great. Cough, spit, get the boat on plane and I'm thinking I'm a regular genius. A few more turns around the lake and you guessed it, the invisible switch gets thrown and the Merc sputters back to the ramp. This time with #2 plug heavily carboned over with dry black material.
I now discover that the rectifier plastic looks "bubbly" and there isn't any continuity from any terminal to another, so I replace it and top up the battery because it hasn't been getting any sort of charge has it?
Now on Saturday the 18th my son and I go back to the little lake where this thing runs smooth and so fast it scares the 9 year old. We head back to dock and make plans to go tubing the next day.
This time it's with the wife along and the engine misses and sputters the entire time. Limp back to shore with six sets of eyeballs glaring at me and I'm feeling like a fool.
Has to be ignition right? After hauling it home, I start pulling spark plugs. Whereas before I was getting 3/8" to more than 7/16" of blue spark, all six are now showing 1/4" max spark.
Those are the symptoms, now my thoughts, even though they might be wrong: stator on this motor serves only to charge battery (it'll run without the two yellow wires hooked up to the rectifier even), so that's probably not the culprit.
The switchbox is providing electricity to the coil and distributor to operate. It doesn't determine if the spark is hot enough does it? My testing on shore confirms that it's a weak spark not an absent one. Can I say the switchbox is OK? How about the distributor?
At the moment I think it could be the coil but far more likely the battery. Let's just say that I don't have a lot of confidence in this particular battery even though it spins the motor over. Will a bad battery keep this ignition system from performing?
Since then I have torn apart the carbs (not especially gummed up,) soaked them in cleaner, installed new gaskets, new needles and seats. Checked to float levers to make sure they measure correctly. The fuel pump was overhauled last fall and the diaghragm is still fine (no leaks, dry on the back side).
Compressions are 115, 111, 115, 118, 112, 113. New Champion plugs were put in this spring and I have month old plug wiires in place. I followed this up with most of a can of Sea Foam thru the fuel line. It was some pretty ghastly smoke there for a while though.
I took it over to the local lake and while bothered only by some mild sputtering trying get a hole shut with the overhauled carburetors, things worked great. Cough, spit, get the boat on plane and I'm thinking I'm a regular genius. A few more turns around the lake and you guessed it, the invisible switch gets thrown and the Merc sputters back to the ramp. This time with #2 plug heavily carboned over with dry black material.
I now discover that the rectifier plastic looks "bubbly" and there isn't any continuity from any terminal to another, so I replace it and top up the battery because it hasn't been getting any sort of charge has it?
Now on Saturday the 18th my son and I go back to the little lake where this thing runs smooth and so fast it scares the 9 year old. We head back to dock and make plans to go tubing the next day.
This time it's with the wife along and the engine misses and sputters the entire time. Limp back to shore with six sets of eyeballs glaring at me and I'm feeling like a fool.
Has to be ignition right? After hauling it home, I start pulling spark plugs. Whereas before I was getting 3/8" to more than 7/16" of blue spark, all six are now showing 1/4" max spark.
Those are the symptoms, now my thoughts, even though they might be wrong: stator on this motor serves only to charge battery (it'll run without the two yellow wires hooked up to the rectifier even), so that's probably not the culprit.
The switchbox is providing electricity to the coil and distributor to operate. It doesn't determine if the spark is hot enough does it? My testing on shore confirms that it's a weak spark not an absent one. Can I say the switchbox is OK? How about the distributor?
At the moment I think it could be the coil but far more likely the battery. Let's just say that I don't have a lot of confidence in this particular battery even though it spins the motor over. Will a bad battery keep this ignition system from performing?