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Charles, Marine Mechanic
Category: Boat
Satisfied Customers: 3979
Experience:  US Navy (Ret) Certified Mercury Marine Tech with over a decade of repair experience.
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2002 Four Winns 190 horizon 4.3GL Volvo penta sx drive. When

Customer Question

2002 Four Winns 190 horizon 4.3GL Volvo penta sx drive. When putting the boat in I turn the key to wait for longer than the two beeps and I can hear the fuel pump working. It is not whining. The boat will run great and I will go over to the dock to load up. The boat will run fine running across the water with the throttle almost at full throttle. It feels like it begins to lose power after the third or fourth pull (wakeboarder). When trying to pull an inexperienced wakeboarder going from neutral to full throttle the boat does not engage and sputters to have a few second delay in the engine engaging (This is typically the last wakeboarder). After pulling wakeboarders or tubers we will anchor for 30 minutes to an hour with the blower on we will try to take off and it will start for a few seconds and sputter and die. I leave the key on and assume that the engine is lacking fuel. After about a minute of it dying it will start right back up with no problems. I have an intermittent mild backfire. After shutting it off it will intermittently diesel. Some times the diesel does not occur and other times it will diesel for 3-10 seconds. I have recently replaced the spark plugs, fuel filter, drive belts, and blower. I am putting premium fuel in the boat and I also put sta-bil 360 marine fuel stabilizer. Do you believe it is a anti-siphon valve, low pressure fuel pump, high pressure fuel pump, timing-distributor-rotor-cap? I have not replaced these items.
JA: Sometimes boat issues seem like they'll be really complicated, but end up being easy to fix. The Marine Mechanic I'm going to connect you with knows all the tricks and shortcuts. Is there anything else the Marine Mechanic should be aware of?
Customer: I believe it is summed up above.
Submitted: 1 year ago.
Category: Boat
Expert:  Charles replied 1 year ago.

Hello, my name is***** will assist you.

Customer: replied 1 year ago.
Hello Charles. Let me know if you need any additional information
Expert:  Charles replied 1 year ago.

The issue that you are having is inside the carb. when it is bogging after the engine is hot, you are lean on fuel. when you turn off the hot engine, and fuel that is coming from the carb is being flashed off in the cylinders, this is what is causing the dieseling. you are going to need to remove and clean the carb. Making sure to reset the float height and the mixing screw to the proper settings.

Customer: replied 1 year ago.
This is the cause for the loss of power on the last wakeboarder and the engine shutting off after it has been sitting for a while? The dieseling occurs intermittently and it seems to be mild.
Expert:  Charles replied 1 year ago.

The engine shutting off, would be from vapor lock. This could be a weak pump or the engine compartment is getting too hot when running. If the cooling system has not been serviced this year, you should do so.

Customer: replied 1 year ago.
To recap your statements.1. The dieseling could be eliminated by the carb. Cleaning the carb, resetting the float heights and mixing screw to the proper settings.2. The shutting off could be from a vapor lock, bad fuel pump, or cooling system.3. The loss of power at the last wake boarder or skier from neutral to full throttle is due to the carb as well?
Expert:  Charles replied 1 year ago.

Yes on all 3 acoc**ts