fuel pumps

(wakepunk16) · (wakepunk16) **Join Date: May 2005** 07-18-2006, 5:11 PM

i have a 03 moomba LSV and in the last 2 years i have blown out 2 fuel pumps, i live in northern wisconsin where we only get to ride 4-5 months out of the year yet im wasting a week or two to get a fuel pump replaced. Im wondering if anyone knows what could be causing me to blow fuel pumps, it seems both of the pumps went out around now when the water gets warmmer then usual, could that have something to do with it? or any other ideas?

(dc9669) · (dc9669) **Join Date: May 2005** 07-19-2006, 7:58 AM

Do you run the boat often with less than a quarter tank of gas?

nautique226 07-19-2006, 8:14 AM

What type of fuel pump Carter? If they run dry they it will burn up.

(wakepunk16) · (wakepunk16) **Join Date: May 2005** 07-19-2006, 2:18 PM

by run dry you mean no gas... and yea i do run with low tanks often can that cause it to go faster

(skibum69) · (skibum69) **Join Date: Aug 2004** 07-20-2006, 10:07 AM

Yes they will burn up faster when you consistantly run with low levels of gas in the tank

(rodmcinnis) · (rodmcinnis) **Join Date: Sep 2002** 07-20-2006, 10:49 AM

Chris:

Can you provide some details about the pump failures?

Are you running along, everything fine and then the pump suddenly stops working while you still have plenty of gas in the tank?

Do the pumps fail to work properly at the start of the season after having sat all winter?

Do you try to stretch the tank a bit too far, run out of gas and then can't get the pump to prime again?

I just can't believe that the level of gas in the tank will have any impact on the life of the pump. The work the pump does is a function of the difference between the pressure at the input and the pressure at the output. The effect of the gas level in the tank will be approximately 1/3 PSI per foot, so if your tank is three feet deep the pump will have to create one additional PSI to maintain the output pressure. I suspect that that is way less than 5% of the total pressure the pump provides.

What is common on fuel pumps, especially in a boat, is for them to fail to prime. Fuel pumps are designed to pump liquid, and they don't pump air very well. When you run the tank dry the pump will have to pump air until it can draw gas from the tank. A boat will have the gas feed draw from a dip tube on the top of the tank, and then there is typically a fuel filter/water separator between the tank and the pump. A slightly worn fuel pump might not be able to create enough suction while pumping air to draw the fuel.

(wakepunk16) · (wakepunk16) **Join Date: May 2005** 07-20-2006, 2:52 PM

we are about 3 months into our wakeboarding season here so we have been going hard for 3 months and the last fuel pump went out wiht about a month left of riding last year so this pump only has about 4 months on it.. the night before we had ran the tank not empty but down to E for sure, i then filled up the tank took it out ot the lake and only about a hundred yards to a dock. i ran the boat up the lake and back and put it back on the dock.. about a hr later went to go wakeboarding it started up and i pulled off the dock a ways to load the ballast and when i tried to start it agian nothing.. just turring over but no fire..

i hope this can help a little bit..

(jzd) · (jzd) **Join Date: Jul 2005** 07-20-2006, 3:05 PM

Electric Fuel Pumps Will run hot with little or no fuel to keep them cool. Are you replacing the filter as well ? Try not to run below 1/4 tank see if that helps.

(dc9669) · (dc9669) **Join Date: May 2005** 07-20-2006, 7:27 PM

Running with less than a quarter of a tank on a regular basis is bad on the pump.

Also check to make sure the relay that brings on the pump is not sticking. Sometimes that can happen and will greatly shorten the life of a fuel pump.

If all else fells sell it and buy a new boat :-)

DC