M40D Tohatsu Top Cylinder No Spark

[me262]

Boat starts right up. Compression from top to bottom....125.....130....140

No spark at top cylinder. Changed top and middle spark plugs. No spark at top cylinder. Took coil off and tried to test it. No reading anywhere with digital meter. Ordered a replacement coil...not original part as could only find used. Hooked it up. No spark at top cylinder. Cleaned as best I could the magnetic sensors on flywheel. No spark at top cylinder. So now I'm stuck. CDI issue????

 

[pvanv]

How did you decide you needed a coil? Whip out your trusty Factory servicer manual, and dx the ignition system. Test each exciter, each pulser, and tast the ignition coil with a good ANALOG meter. Incidentally, the OEM coils are still available:

3C8060480M

IGNITION COIL (WITH RESISTANCE)

$59.20

 

[me262]

Tested coil with multimeter. Got no resistance anywhere

 

[me262]

Bought coil je-x020006b from jetunit. Looks like original.....came up as direct replacement

 

[Panga]

Swap coil from either of #2 or #3 cylinders. If it's a dead coil, #1 cylinder will fire and one of the bottom cylinders will misfire.

 

[me262]

Already replaced coil

 

[pvanv]

Tested coil with multimeter. Got no resistance anywhere

No resistance as zero ohms, or infinite ohms? The secondary side should be near infinite to ground.
What do the pulsers and exciters show? Did you do the CDI tests?

 

[me262]

Ok....as last resort I tested wire from cdi to coil. Np resistance. Pulled it out of the plastic sleave that it shares with the other 2 coil wires and....sure enough...it was linked and broken. I attempted to cut the wire back so I could splice on a new one but wire disintegrated all the way back to the cdi. So....now I either try to open up the cdi to attempt a repair....try to buy a used cdi (proving difficult to find)...or get another motor as the new cdi boxes for these are not available. Any ideas out there???

 

[me262]

And...Paul....I know you mean well....but you are doing outboard repairs for a living and your diagnosis techniques are way above the average guy on here..
.

 

[pvanv]

There is no information in "no resistance". Either Zero or infinite might translate to that, but it was not mentioned. That has nothing with repairing outboards... But basic knowledge of how to operate an ohm meter. Electricity 101. We learned that in Junior High.