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ematthew
07-20-2005, 11:23 AM
Had a strange problem with my 2003 205V with Predator engine yesterday. The gas tank was about 1/8 to 1/4 full, and while riding with the perfect pass at 22mph I turned left and the engine RPM bogged down and the boat came to a stop with the engine at idle. I thought the problem might be with the perfect pass, so we rode some more without it, and a similar occurence happened a few minutes later. The boat just slowed down from about 20 MPH to idle speed, with the tach dropping about 10. I was getting low on gas anyway, so we idled to the gas dock to fill up and I phoned my MC mechanic and told him the story. He thought possibly that we had some bad gas with water in it, and suggested we fill up and see if the problem recurs. After fillup, the boat rode fine without a recurrence for the next hour, until I hit a stump, bent the prop, and had to limp home which is another story entirely!
Any thoughts on the cause of this problem? Could "watery gas" cause the engine to bog down and lose RPM when the tank is close to empty? Any other possible causes?
Thanks for any input.
Ed

east tx skier
07-20-2005, 12:39 PM
Where is the fuel pickup located? Sorry to hear about the stump. Been there.

ematthew
07-20-2005, 01:30 PM
I am really not quite sure. I know there is some kind of pump inside the fuel tank. I am not all that knowledgable about the engine, but I do know how to change the prop which I will be doing this afternoon.

bigmac
07-20-2005, 01:49 PM
Had a strange problem with my 2003 205V with Predator engine yesterday. The gas tank was about 1/8 to 1/4 full, and while riding with the perfect pass at 22mph I turned left and the engine RPM bogged down and the boat came to a stop with the engine at idle. I thought the problem might be with the perfect pass, so we rode some more without it, and a similar occurence happened a few minutes later. The boat just slowed down from about 20 MPH to idle speed, with the tach dropping about 10. I was getting low on gas anyway, so we idled to the gas dock to fill up and I phoned my MC mechanic and told him the story. He thought possibly that we had some bad gas with water in it, and suggested we fill up and see if the problem recurs. After fillup, the boat rode fine without a recurrence for the next hour, until I hit a stump, bent the prop, and had to limp home which is another story entirely!
Any thoughts on the cause of this problem? Could "watery gas" cause the engine to bog down and lose RPM when the tank is close to empty? Any other possible causes?
Thanks for any input.
Ed


I'm gunshy of that "losing RPM" as those were exactly the symptoms of my 230VRS/MCX as the fuel pump was going out (with 4 hours on the engine, soon as I got to about 1/2 tank). I took it in the next day. They ran it around the lake and it was then working fine, so they put the service manager's son in the boat and told him to drive it around fr an hour or so. Finally, he came back after about 1/2 hour and reported that it has started doing it again, they replaced the fuel pump and it's been fine since, over the next 15 engine hours.

djhuff
07-20-2005, 02:28 PM
I've also heard that if the fuel filter is a little clogged, it will do this at lower gas tank levels because the pump has to work harder to get the fuel through the filter. Won't do this with a full tank because the gas is putting pressure on the filter.

ematthew
07-21-2005, 05:28 PM
Thanks for the input. I went back to the boat yesterday, swapped out the mangled prop, topped up the tank to full with premium gas from the local BP Amoco station, and ran it for about 2 hours. No problems at all with losing RPM. It could be that my mechanic was right and it was bad gas, but I am betting there is some problem with the fuel pump and/or fuel filter that shows up only when the tank is very low. We'll see what happens as I use the boat over the next few weeks. I might just have to keep a relatively full tank of gas at all times until I put it away for the winter and have the fuel pump examined then. Hopefully I won't lose any time on the water this summer, but we'll see....
Thanks again for the help.
Ed