Engine only runs out of the water

[Dave Rintel]

If this has been posted before please point me to the thread. I started the day with a blown 20 amp fuse and the right engine wouldn't start. I replaced the fuse and everything seemed fine until about an hour of running. Then the engine wouldn't idle well. That progressed to not starting....well kind of. It would start and run as long as I held the key in "start" (as best as I could tell as I didn't want to leave it there for more than a couple of seconds). The fuse is still good. I pull the boat out of the water and flush the left engine. Then I habitually flushed the right and realized it was now running fine. Back in the water it goes. Right engine won't run, just some sputtering. Out we go again. Runs fine. Thoughts?

 

[Bruce]

Dave, where was the blown fuse located?

The engines require greater torque to run in the water than out of the water.

The first thing that I would do is change the spark plugs. Then I would check the air filter to verify that it does not have oil clogging it. Next I would move on to verifying that the engine has sufficient fuel flow.

 

[Dave Rintel]

Ok, I'll start there. Air filter is ok. I am hoping it's not something bigger based on the blown fuse. I had the boat out of the water for several months working in the other engine (dreaded water leak in#3). This is the second time I've run it since. I had the gas drained while it was out so the fuel is new. How would you suggest checking the flow?

Spark plugs in the morning.

 

[Bruce]

You might swap the fuel lines between the two pumps as a way of checking the fuel flow.

I am hoping the spark plugs resolve it.

I am assuming that the blown fuse is the one in the house (accessory) circuit not one of the ones in the engine control boxes. If that is the case then the two issues should be unrelated. The engines will start and run without house power.

 

[Dave Rintel]

The blown fuse is the one in the control box, I think. It's the one under the three inch screw off cover, directly above the starter solenoid. The engine would not start, not even turn over, until I replaced it.

 

[Boat Crazy]

Safety switch on your clean out tray out of adjustment maybe. Tape a coin above both switches on lid (they are sometimes reversed) to test if that helps.

 

[Dave Rintel]

It runs fine out of the water.... Wouldn't the safety switch have to work for this? I'll try anyway!

 

[Bruce]

The fact that it runs out of the water makes me believe that the computer is ok.

 

[Gym]

@Dave Rintel I had the exact problem. The port engine would start but stop when I released the key. If I held the key in the start position it would continue to run until I released it. I thought it was an ignition switch so I changed it but didn't fix the problem. I got into the wiring connections in the stern starboard locker access port. I found several wet connections. I dried and sprayed some electrical drying agent on the connections and currently it runs fine.

I suggest you look for water and/or corrosion in those connections. The one that was very wet was way down in the hatch and was difficult to reach. I couldn't pull it out very far so you may be able to access it better by pulling the clean out tray.

 

[Dave Rintel]

@Gym, I'll be opening that up tomorrow to hook up the YDS so I'll be sure to look. I didn't get to the spark plugs yet, shooting for tomorrow.

Thanks all!

 

[Boat Crazy]

It runs fine out of the water.... Wouldn't the safety switch have to work for this? I'll try anyway!

If the boat is rocking enough to cause the hatch to lift it could be possible.

 

[Dave Rintel]

Kill switches are ok. I changed the spark plugs. The old ones looked ok to me. Dry and electrodes were good. No issues getting them out (even #3). Maybe a bad coil?

I couldn't find my YDS cable so I'm stuck until I get a new one. I did open the cover in the starboard stern locker and check the wiring. It was a little stiff but no corrosion or wetness. Oddly, when I left the boat two days ago the 20 amp fuse on the computer was fine. When I got to the boat today it was blown. What would blow a fuse with no power applied? I'm actually going to start a new topic on that question.

 

[Bruce]

What would blow a fuse with no power applied? I'm actually going to start a new topic on that question.

If that fuse was the original fuse it has 10 years of use. I assume that it would be a manufacturing defect that showed itself over time.

 

[Dave Rintel]

Bruce, I've been through three fuses in a week! I split this off into another thread too.

 

[Bruce]

Bruce, I've been through three fuses in a week! I split this off into another thread too.

You have me wondering what could be drawing too much amperage.

Does the starter engage immediately? The solenoid could possibly be the culprit.

My next thought would be that you have a wire shorting somewhere. Have you checked the plug wires for any damage?

 

[Dave Rintel]

I'm fairly used to changing the solenoids (I've gone through 4 in ten years of salt water). I'll try to check them. They engage and disengage normally. Between the two issues, I'm starting to lean toward a plug wire or coil problem.