1997 Johnson Fast Strike 115hp

[Jacob645]

I'm having a problem with my new boat. The very first run everytime I go out is perfect. Ater the motor warms up it starts to cut out really bad, like it's dropping a cylinder or something. It sometimes will kick back in momentarily but the cut out again. The motor never completely dies which leads me to believe it's just one cylinder. It idles great. Any ideas?

[tashasdaddy]

check you spark or all 4 cylinders, immediately (on the water) when it does this. sounds like you have a coil heating up and failing. the only way to find it is immediate check, before it has a chance to cool down.

[Jacob645]

This has the Optical Ignition Stystem. The coils don't look like they do on my old 1975. Can you replace just one coil or do you have to replace the whole assembly?

[tashasdaddy]

find out what you problem is, before thinking about replacing parts. these parts get expensive, until you do the spark test, you have no idea what to replace. it has dual coils, which server 2 cylinders, 1/2 of one could be bad, or the complete coil, killing 2 cylinders, those motor will run on only 2 cylinders.

[Jacob645]

Sounds good. What would be the best way to do that while on the water?

[Jacob645]

Is there a way to test the power pack to make sure it is sending power to the coils? After looking around on the forum, I found another post that had my exact same symptoms. He said it was the power pack that was going out and only giving spark on cylinders 1 and 3. It would be worth it to me just to replace the power pack anyways, as I've heard they are usually a problem with these motors.