Fuel System Problems?/ Engine stalls

[BC98]

Ok, fellas, you have helped me out in the past so let me fire one at you. I have an old 98 PRE 2002 WT that has a carburetor and points, etc. Last year at the beginning of the season, I took the boat to the lake and for the first hour or so it stalled out several times and finally cleared out and ran normal the rest of the season, I changed out the fuel/water separator to make sure that wasn't the culprit. It ran smoothly at idle and after the stalls stopped so I didn't figure it was electrical. Two years ago I replaced the fuel pump as well.

This season after changing the oil, cleaning up the boat, etc., I took it out for a shakedown to get ready for the year and the same problem occurred, only this time it did not clear up. It eventually got to the point that the engine would run for about 10 seconds and quit. I had to continually restart the motor to make it back to the dock. Fortunately, I stayed close to the shore.

I cleaned the carburetor up for good measure and changed the fuel/water separator out again. (I did not see any water in the old one after taking it out.) Took the boat out again and it ran good for about an hour (with only two brief stalls) and then totally stalled out again the same as before and I had to limp back to the dock.

I suspect maybe water in the fuel that is making it past the fuel/water separator? Does that make sense? The only other thing I can think of is that for some reason the fuel pump is running intermittent and unpredictably. My next thought is to totally drain the tank and put in new fuel. Any input from you guys would be great. Thanks for the help!

[PaceWithGrace]

Moisture in distributor cap, or condenser may be going. Google for more info.

[lee]

Take the liquid from the fuel filter and pour in a glass jar and see what happens to it.

[UNSTUCK]

How did you clean the carb? Full tear down and rebuild?

[BC98]

Take the liquid from the fuel filter and pour in a glass jar and see what happens to it.

I did this. Fuel looked clear of water. There as a tiny bit of dirt but nothing significant.

[BC98]

How did you clean the carb? Full tear down and rebuild?

No on the full rebuild. I am taking the carb off tomorrow and taking it in for a full rebuild. Maybe that will solve it? Maybe the jets are gummed up.

[BC98]

Moisture in distributor cap, or condenser may be going. Google for more info.

I don't believe it's an electrical problem as it ran good for a period of time after a light carb cleaning. It idled well too. I'll check for moisture though just in case. Thank you all for your input. Going to rack out for the night. I'll check for more responses tomorrow. I appreciate it.

[BC98]

Update: I took the carb in to National Carburetor to have them rebuild it. Prior to rebuilding any carbs, they test them to make sure you have an actual problem. The carb performed like a champ. I think my next, easiest step is to drain the tank and check for water. If that doesn't work maybe the electrical stuff is the problem. It confuses me that it would run so well for a short period of time and then start up, run momentarily, and then lose power and die. Restart is always immediate with a smooth idle. I don't get it. It simply won't maintain the power.

[JCP]

Sounds like low volume fuel delivery to the carb. It eventually gets enough to fill the carb bowl and allow a short idle time until the bowl runs dry. Disconnect the fuel line inlet at the carb and check for fuel flow. Probably need to do this for at least 2 minutes to make sure it has a continuous steady flow. You might need to keep cycling the key to keep the pump running or wire it direct for the test.(assuming it is an electric pump) If it seems to flow slow or starts to flow good and then slows down, I would suspect a fuel filter. Make sure that there is not another filter in the system that you have not found, many boats have 2 inline filters plus a filter at the carb inlet line.

[BC98]

Ok. I checked the fuel pump by disconnecting the line as mentioned. Fuel continuously feeds from the line. I traced the line from carb to tank and found no other filter (it's an older boat, 98).

Next I tried replacing the coil with no positive results. I also tried the ignition sensor just for fun. No change. The only other thing I can think of is maybe the ignition control module? It appears the auto advance is controlled electronically through the ICM. Running out of ideas. A new ICM is $500. Ouch! Not sure if there's a way to test the old one first.


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