My son has our rig (09 GT w/GTR35) at the coast. He just called me and said that everytime he hits some rough water it starts missing out bad...even died on him once. He said it runs great in the calm waters around the back bay islands. Why would a rough ride cause the motor to miss out/die???

Sounds like a loose wire some where.

check the key switch wire running on the left side of the motor it may be nicked this cause motor to miss

One time I was in POC with my PD and i was getting a misfire. Ended up being a bad spark plug wire that was arcing due to the high salt content in the water. When the water smoothed out, no miss, but when it was rough it was bad. Could be any of the above stated also??

X2 on da spark plug wire!

Sounds like the wire that runs from your coil is grounding out against your intake!! Most likely rubbed a raw spot in the wire

Need to replace the rotor and gurter

Well, now it seems the cause isn't so much the rough water as it is the water (spray) splashing the motor. Whar would cause the motor to miss out just because some saltwater (not alot) is spraying the motor?

Go back to fourth post! Saltwater is more conductive. If you have water splash coming up around the spark pulg wires and there is a crack in one of the wires it will arc off, causing a misfire!!! You might think it sounds stupid but it happens. I never believed it until I will going out on a hunt before day light and was getting a mis and looked back to see the arc myself. It's not easy to see in the daylight but it's there.

X4 on da spark plug wire!!!!

When it gets dark tonight, go outside, start your engine and have someone run it up to about 2000 rpm and hold it there.

Take a spray bottle of water and start spraying your Spark Plug wires, you will then see the arc.

See there!! If River says so! Then thats the problem!!!

yous mite wont too lookee ands sawe ifs thee sparkie plugg booth iss knots touchin thee guarde whair its makees a nintee. ifs its touchin juss takes a sockit ans a hammir ands bends thee piecee off guarde downee

Translated by girlfriend:
you might want to look and see if the spark plug boot is not touching against the guard where the boot make a ninety before it plugs into the plug. If it is touching then take a socket and lay it against the guard where it is touching and knock it down a little making a little U in the guard.

He will getting home with the boat this afternoon. I will check all those things and let you know what I come up with. thanks for all the advise.

Checked every electrical connection I could find on the motor and I can't see anything wrong. Did like ya say and waited till dark..ran motor at around 2200rpms and sprayed plug wires with water and don't see a problem. I had my son in the boat with motor running, both in neutral and forward, while i sprayed the heck out of it with water hose and it never missed out once. I am going to run it tomorrow on the river and see if it gives me any problems.
Here's a side note....before he left for the coast my son changed the oil and he over filled a little..not much. That wouldn't cause any issue would it?

Scotty, did you check your coil wires?

Help a brother out cuase i'm no mechanical genius...do you have to take anything off to see the coil wires?

Yes. Pull off the front cover and you will see your 2 coils with a wire connecting them to your kill switch and/or key switch. These wires are known to chaffe and can cause your engine to do exactly what it is doing and/or not run at all.

I did not take the cover off but i was able to look under the cover at those wires that run to the switches and they looked good. Tomorrow I will take that cover off and inspect them better.

All connections look good. I ran it on the river for a while and it never missed out once. Splashed water on it, went over some choppy water, and ran like a top. You got me on what it was doing at the coast with my son. Unless the saltwater makes a difference.
I do have 2 issues from today. It seems to be making a "grinding" noise when trimming up AND it pulls to the right bad. Even with the tiller handle resting against my left leg it was hard to handle. Guess I'll be bending my skeg plate.

I had the exact same thing happen on my 36 PD. It was not the spark plug wire. The cause was the spray was getting into my air filter and bogging my motor down. Take your air filter cover off and see if the metal on the air filter is rusted. Im betting it is from the salt spray. There are two holes on the back of the metal plate that the filter screws down to, put a bead of caulk in them to close them up. I also noticed that when I put my hand over the air intake on the plastic housing and revved the motor up, that it would not starve the motor of air and die. So I ran a bead of caulk around the plastic housing where it meets with the metal backing plate. I also ran a bead on the plastic screw cap that holds the entire thing on. After the caulk set up, I cranked the motor again revved it up and covered the intake with my hand, it killed the motor, telling me it was only sucking air from this spot now. I have never had the problem since doing this even in rough water and salt sprays.

Saltwater makes that big a difference!! Mine never did anyting until I put it in saltwater!! Your plug wire will arc off of the metal cover that is around the head.