Engine Surging In Rough Water Only....

[ScottWyler]

Hey everyone, I have a 99 ox66 225hp in mint condition and the only issue I am having is that when I am in rough water the motor is surging and loses power and the regains it. It happens when I am in only rough water and smacking against waves. I noticed that when it happens and I put my hand on the throttle I feel a large vibration in it and sometimes when the motor stalls from this issue..the throttle handle is vibrating so much and even makes a loud noise. My VST is clean and was looked at by my mechanic so I was wondering if this throttle box is an issue? I do know that my mechanic said it may be so I was just wondering for outside opinions and if anybody else has heard of this issue or dealt with it in the past. Thank You!!

 

[racerone]

You might want to look at flywheel magnets.----Do not ask why at this time.

 

[dingbat]

No water in separator?
OEM fuel pump and fuel lines?
Fuel tank(s) levels?

Ran into this problem a number of times over the years. Most turned out to be problems related to fuel delivery systems.
The pounding shakes up all kinds of things in the bottom of the tank. Low tanks levels (sloshing) increases the amount of vacuum required to draw fuel. Vacuum leaks in the fuel line only exasperate the problem.

Bad/sticking anti-siphon valve. Leaking tank selector value. Vacuum leak(s) in fuel lines. Clogged tank pickup (wild cherry seed)

 

[Faztbullet]

Sound like you have loose throttle cable in box

 

[ScottWyler]

Sound like you have loose throttle cable in box

but what is the significance with rough water only is when this happens.. always when I am going over rough water and waves.

 

[ScottWyler]

Maybe this throttle control is defective? it could be aftermarket and it is overstroking?>?

 

[dingbat]

Maybe this throttle control is defective? it could be aftermarket and it is overstroking?>?

Is the motor surging (RPM up and down) or not maintaining throttle position (slowly going faster or slower over time)?

 

[ScottWyler]

Is the motor surging (RPM up and down) or not maintaining throttle position (slowly going faster or slower over time)?

surges like crazy almost like 2K worth of rpm