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Is there any way that intermittent spark on cylinder 1 could be caused by fuel 1996 15hp

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Barnaclebill1

New member
Cylinder 1 is misfiring badly only an low speeds seems ok at wot
There is some juice being put out . I can tell because I put my pinky finger in the boot and pointer on the block and I can feel it it's a little stronger on cycl 2. Was misfiring on the river pulled the boot off cycl 1 no change pulled boot off cycl 2 motor died . Please help I have like a week left of the fish being here and all I've done is work on the boat
 
Probably not from the fuel.
Try swapping the coils/moduals around and see if the problem fllows the swap?

You might need a special meter to do some tests???

No fire or Intermittent on One Cylinder:

  1. If the cylinders are only acting up above an idle, connect a inductive Tachometer to each cylinder in turn and try to isolate the problem cylinder.
  2. Check the trigger resistance and DVA output as given below:
WireRead ToResistanceDVA
Brown wire (#1)
Brown wire (#1)
White wire (#2)		White wire (#2)
Engine GND
Engine GND		800-1400
Open
Open		4V or more
1V or more (a)
1V or more (a)

  1. This reading can be used to determine if a pack has a problem in the triggering circuit. For instance, if you have no fire on one cylinder and the DVA trigger reading for that cyli?lder is low — disconnect the trigger wire and recheck the DVA output to ground from the trigger wire. If the reading stays low — the trigger is bad.

  1. Check the DVA output on the green wires from the switch box while connected to the ignition coils. Check the reading on the switch box terminal AND on the ignition coil terminal. You should have a reading of at least 150V or more at both places. If the reading is low on one cylinder, disconnect the green wire from the ignition coil for that cylinder and reconnect it to a load resistor. Retest. If the reading is now good, the ignition coil is likely bad. A continued low reading indicates a bad power pack.


OR try this as the system is Mercury.

No Fire on One Cylinder:
​
  1. Check the DVA output on the green wires from the switch box while connected to the ignition coils. Check the reading on the switch box terminal AND on the ignition coil terminal. You should have a reading of at least 150V or more at both places. If the reading is low on one cylinder, disconnect the green wire from the ignition coil for that cylinder and reconnect it to a load resistor. Retest. If the reading is now good, the ignition coil is likely bad. A continued low reading indicates a bad power pack.

 
Ok I'll switch them and see if it follows . Thank you for the reply! I'm going to try to post some photos. I love adding photos when I can so people like you can use them
next time someone needs help . My way of contributing as I lack the knowledge to give much advice
 
Recoil and flywheel
 

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Inside of fly wheel
 

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More photos
 

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Also I have a slight leak in my fuel pump found this gasket while removing flywheel.
I knew something was wrong because I had a drip when I would first prime then it would stop and I would lose prime after it was shut down . That's why I asked if it could be fuel also I have never drained the bowl on this thing . Musta dropped it last time I cleaned the filter on a island by moon light. Crazy it even runs without it
 
I switched the ignition modules the problem did indeed follow the switch. cylinder 1 is firing now and cylinder 2 is intermittent mostly not firing .
 
Missing gasket :)
These little motors seem to run just about forever even missing parts.
Since the spark problem changed when you swapped the parts, Replace it.
 
Ok so I just got it into the water last night I was under the weather for a bit . The new ignition module appears to work just fine�� it idles and runs at low end great ! Alas it appears I messed something up in the mean while because now once I get to half throttle it falls on its face . If I give it full throttle in fwd gear from nothing it jumps right to it then slowly the revs drop until it coughs out entirely. Not fun in the dark on the hudson river in a 14 ft gamefisher and you can't outrun the barges . I did replace the plugs with two from the marina when I bought the ignition module. They off by one number from what I could find . But my guess is that this is a fuel problem.
 
Yes a fuel delivery problem.

Is the tank vent open?(had to ask)
The inline connectors, they have rubber seals that go bad.
I just remove them all and go direct from the tank to the ball then to the pump.

Make sure the ball pumps up firm.
Then after it starts it should get soft, not collapse but soft.
Check the diaphragm in the pump, no holes.
The primer could be bad too??

It also sounds like it might be getting hot??
Temp gun $16 eBay
 
Yes the vent is open I often wonder if the little rubber gasket laying where the air enters the tank would close it off too much . There are no inline connectors directly from tank to bulb to fuel pump. I don't think it softens after it runs for a minute because while it's running poorly I tried to squeeze the ball and it was stiff . Ill look into a temp gun . Maybe i messed up putting the found gasket back in place
 
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