So it doesn't appear to be the spark plugs...need some help here - RESOLVED

[Scuba_ref]

Over the past week this has been my experience: One week ago the port engine was running really rough and after some time on the water I was able to get enough out of it to keep boating. Due to that rough running I replaced the spark plugs in that engine. After that it ran great. Yesterday I take a buddy out on the water to have him try surfing and after 10 minutes of running the starboard engine starts acting just like the port engine had last week. I replaced the SB spark plugs and we are back up and running - although it wasn't immediate, meaning it took the engine a minute or two to get running to 10K rpm. So today out with the youth group from church and we idle away from the dock and both engines start acting up (similar to the earlier events, rough idle, idling at half the rpms and then both engines die and won't restart) we get towed back to the dock, I pulled the boat and here I sit at the computer instead of at the helm.

Any ideas what might cause one engine to act up and then at a different time the second engine to act up and now today both engines to act up? Remember they both have fresh spark plugs.

 

[Murf'n'surf]

Bahamian fuel!

I'm thinking a fuel issue.

 

[thcole]

My guess would be bad gas. Have you used it much this year, it sounds like you have. So maybe bad from the gas station.

 

[itsdgm]

A few things that come to mind:

1. an exhaust leak inside the engine compartment. Check all of your clamps to see if any are broken. Next time out, try running with the blower on to increase air flow and/or run with the engine cover open to get even more fresh air in there. If exhaust is leaking, it will choke out the engines in the enclosed space.

2. Possibly bad fuel?

3. Check the air cleaners to see if there's any oil on them.

4. Check all battery connections. Possibly take it in and see if the battery needs charging or possibly had a bad cell

Good luck, hope you figure it out soon!!!

 

[Scottintexas]

do you have a maintenance manual?
Do you have a YDS ?
The fact that both engines are experiencing problems I think is good unless each engine has separate problems then it's really a troubleshoot,

I would look at things that would make both engines have problems.
Is your battery good are the cables (especially negatives) attached good (I had a stalling problem because of this)
Fuel - any new gas station you used or did the boat sit for a while
Air - are they being starved, maybe try running with the engine hatch open
safety lanyard
I would also probably bypass the clean out hatch cover just to eliminate it being an intermittent issue

The YDS might give you more insight especially if each engine has a different problem.

 

[Scuba_ref]

A couple suggestions I can rule out:
1. Just replaces spark plugs and therefore had a close look at the air filters, they look good
2. We have put about 25 hours on the boat this year so far and so I am going through gas, I mainly use a couple of Shell stations and I just did put some "fresh" gas in the boat
3. I do have the YDS, haven't been successful in getting it to connect and read the engines. I was just reading the thread about switching the com ports
4. Battery connections look to be solid and I have volt meters wired in so I know the status. The starting battery was brand new 2 months ago. I will double check the connections and battery.

I will check the exhaust connections. I did replace my scupper this spring and to do so had to wiggle stuff around down in there. What really confuses me on this is that the symptoms were the same on both engines but they were 5 days apart. I can't imagine a fuel issue in that case. Having said that I'm not at all mechanically inclined and don't pretend to know how engines work.

 

[Scuba_ref]

So I am sitting in the boat in the driveway all hatches open and they won't start. Batteries are holding at about 12.6 volts. I switched the laptop port to com1 and I still can't connect with the yds. Just not going to be my night tonight.

 

[Scuba_ref]

I guess there is some good news...the exhaust clamps all look to be in good shape and tight!

 

[Bruce]

Have you looked at the air filters? Is it possible that the oil was overfilled and the filters are clogged with oil?

 

[Bruce]

Oops, I see that you already checked the air filters.

How did the spark plugs that you removed appear?

 

[Scuba_ref]

More good news, I got the YDS connected and reading the engines. Everything there looks normal. @Bruce the spark plugs that I removed look like this and they all looked like this:

 

[craigm]

My suggestion is fuel pump and or fuel filter.
On your boat they may be integrated so may need to bring it in.

 

[itsdgm]

I ended up having to drain my fuel last spring. It wasn't the hardest thing to do, I don't know why you'd have the same issue days apart like that. But as of now, you're cant get either engine to run?

 

[Glassman]

Fuel filter? Have you pulled it to check? If you did pick-up some bad or dirty gas it would clog the filter so no matter how much new fuel you put in it can't get past a clogged filter.

Just a thought.

 

[Scuba_ref]

Interesting, the fuel filter is part of the pump in the tank right?

I'm curious about my storage situation - we keep the boat in the yard on a patch of driveway that used to go out to the main road and is now blocked off so it really is just parking. That patch of driveway has a bit of slope to it, with the boat backed down the slope. If it is indeed bad gas and or particulate matter or even water in the fuel, based upon my parking on that slope am I putting the boat in a position where all the junk in the fuel ends up collecting back by the fuel pumps?

Anyone aware of a thread with instructions on getting to and cleaning the fuel filters? The fuel pump activated when I toggled it in the YDS.

 

[Glassman]

Interesting, the fuel filter is part of the pump in the tank right?

I'm curious about my storage situation - we keep the boat in the yard on a patch of driveway that used to go out to the main road and is now blocked off so it really is just parking. That patch of driveway has a bit of slope to it, with the boat backed down the slope. If it is indeed bad gas and or particulate matter or even water in the fuel, based upon my parking on that slope am I putting the boat in a position where all the junk in the fuel ends up collecting back by the fuel pumps?

Anyone aware of a thread with instructions on getting to and cleaning the fuel filters? The fuel pump activated when I toggled it in the YDS.

Just open the hatch, you'll see this:

(Photo courtesy of the Muther Tucker thread )

I'd start with the easy one and check the filter at the pick-up. Disconnect your battery and put out that aroma therapy candle and you should be good to go.

 

[Murf'n'surf]

Are there fuel pump breakers in the ECU boxes? (On back wall above engines)

Do you smell gas when trying to start?

 

[Glassman]

Are there fuel pump breakers in the ECU boxes? (On back wall above engines)

Do you smell gas when trying to start?

@Murf'n'surf Are you thinking no pumpy?
You could always pull the hose off the engine and turn the key (be sure to put the end of the hose in a catch can)

 

[subysti]

Don't these boats have dual pumps and pickups? I would guess bad gas or possibly the cut offs under the clean out hatch. I'd by pass the switches there and try and see if it helps.

 

[Glassman]

Don't these boats have dual pumps and pickups? I would guess bad gas or possibly the cut offs under the clean out hatch. I'd by pass the switches there and try and see if it helps.

Did you look at the photo above? Those big round things are the pumps. (The little black round thing with the wires is the fuel level sender.) They are built into the tank and the filter sock is at the bottom of the fuel pick-up. If the filter is clogged the pick-up doesn't pick-up no mo.