Nissan 18 HP 4 Stroke nsf18b2

[rmcgeher]

I have a 2006 Nissan 18 HP. It dies under load.

History
About 5 years ago boat flipped in a storm - freshwater - and the motor was submerged for a couple of hours. It was immediately brought to my mechanic who did what needed to be done to prevent issues.

When I got the motor back it dies under load. Idles fine and runs fine at super low speed, I start to open up the throttle it dies in about 50 feet.

Brought back to the mechanic - he tried everything he can think of - fuel pump, thermostat, nothing obviously wrong. It has sat his shop, unable to figure out.

I grabbed it back and removed carb - did complete and full cleaning and soaking. New plugs, new gas. Fires up. Runs great on muffs, neutral, and in gear no issues no signs of issues. Put on a 16-foot boat, started right up, and dies as soon as I open up throttle, then hard to restart.

Even though this 10 or 12 years old, it has very little hours on it and looks like new. I am at a loss at what to do. I can do simple mechanical things.

If you have tips or suggestions please let me know. Thanks.

 

[Sea Rider]

Seems will need to troubleshoot all electrical components individually, any could be shot to miss when the throttle is in demand. Running while the motor is on Load is everything....

Happy Boating

 

[brim_buster]

sounds like it might be flooding out or running out of fuel. If its hard to start I would look at the plugs after it dies. Is the float set right? A friend of mine had the same issue. He brought it to me and the float was upside down and a local shop rebuilt the carb. I took pics and told him to go get a refund. I have a four stroke 25 merc and it was crappy fuel that gummed up the inside of the carb.That was on me for being cheap and not buying marine fuel.LOL.