1998 Speedster Twin 800's both motors missing

[USAF_Pride]

Ran the boat last weekend for a couple hours and had no issues. During the week, I discovered the PO was using synthetic TCW3, so I drained all the oil out and put in the correct oil. At the same time, I removed the connectors to the engine electrical boxes and wrapped some electrical tape around the top to keep the split loom in place.

Now, upon putting the boat in the lake, both motors are missing. The rear spark plug (towards jet pump) on both motors are wet. I've cleaned the plugs and swapped them front to back and restarted the motors and I still have the miss with the rear plug still fouling. I have also reset the connectors to both electrical boxes.

I can't figure out what is related between the two that would be causing both motors rear cylinder to be missing? Thoughts?

And I changed the beeper out, but I am not sure that is related to the missing. :facepalm:

 

[Sportster-2001-951C-Stock]

Ran the boat last weekend for a couple hours and had no issues. During the week, I discovered the PO was using synthetic TCW3, so I drained all the oil out and put in the correct oil. At the same time, I removed the connectors to the engine electrical boxes and wrapped some electrical tape around the top to keep the split loom in place.

Now, upon putting the boat in the lake, both motors are missing. The rear spark plug (towards jet pump) on both motors are wet. I've cleaned the plugs and swapped them front to back and restarted the motors and I still have the miss with the rear plug still fouling. I have also reset the connectors to both electrical boxes.

I can't figure out what is related between the two that would be causing both motors rear cylinder to be missing? Thoughts?

Shooting from the hip, my first thought is you probably disturbed a common ground that was crusty and needs cleaning/tightening. It kinda matters though, depending on how you boat is configured, some use just one coil to fire both spark plugs and in that case if one is firing then the other almost has too. So, the question comes to, how many total coils does your boat have, just two, or four?

 

[USAF_Pride]

Shooting from the hip, my first thought is you probably disturbed a common ground that was crusty and needs cleaning/tightening. It kinda matters though, depending on how you boat is configured, some use just one coil to fire both spark plugs and in that case if one is firing then the other almost has too. So, the question comes to, how many total coils does your boat have, just two, or four?

I believe there is one coil per engine as I peeked into the electrical boxes and to my untrained eye, it only looks like one.

I actually am starting to think it is the spark plugs. I am going to go get 4 and report back.

 

[USAF_Pride]

Four spark plugs solved all that was ailing it. I wonder if the TCW3 was fouling the plugs and causing the rough running I experienced in the past. Either way, it's fixed and working for the holiday weekend.

Thanks for the quick reply.

 

[RFoster130]

With my 98, any time i had an issue with it running rough, i would start with spark plugs. It always cured the problem.

 

[USAF_Pride]

With all my Skidoo experience, I should have known to start there first.

At least everyone here was nicer than my family when I said "the motors were missing." My wife's response was "Where did they go?"