250XS eating fuel pumps

[Superbender]

The aftermarket primer bulbs are worthless

[Capt.Insane-o]

BRP is the only way to fly...and even then I've had some I put on two years ago that are turning to goo.. though mainly from lack of keeping up on things. What I see more and more of now is filler/vent hose degredation...that turns into some serious warfare on some boats.

[XstreamVking]

Just replaced fuel feed , vent hose and fill hoses that were only 1yr old. Thats not real unusual for the feed line, but even the hoses not continually in contact with wet fuel are coming apart and intermittently clogging fuel pickups. Like the capt said, serious warfare...... Aircraft have to replace hoses yearly, boats may have to also with the wacky fuel we have now..... Most fuel pumps fail from starvation and the associated heat caused by it.......jm2cts...

[spareparts]

check the voltage at teh pumps, make sure you are getting enough while the engine is running, I can't remeber, but I think the ecm controlls the ground feed to teh pump, rather than the + side, cehck to see you are getting 12V betwen the two legs while the pump is running.

[Mr. Demeanor]

The grey Mercury and Tempo fuel hose seems to be a guaranteed failure with ethanol. MotionPro makes an ethanol rated clear fuel line that helps with future diagnosis.

[arrowwaves]

We are blaming the fuel. Even though it tests fine, is only 5% ethanol and is not phase separated. Something in the fuel is causing this, so the pumps have been replaced and the engine has been winterized on an external fuel tank. I am getting the boat back with the instruction to empty the tank and replace the fuel and it should run fine next season. Both pumps are once again locked up. this time they blew a fuse. If you saw the pumps they look like brand new parts, pristinely clean fuel screens. Let's hear what you think!

[AwesomeBullet]

I think fuel restriction! Fuel pumps are designed to push, not pull.....if they have to work hard to pull the fuel from the tanks (hence the need to put a vacuum gauge in the line and see how much suction they are creating tying to pull fuel to the engines) then they WILL overheat and lock up in short order.....Maybe the screens on the pickups in the tank are plugged, anti-siphon valves causing a restriction, etc, but I'd put my bet on the fact that it has a fuel restriction and will cause issues again next season.....

[Euroski]

Doesn't the 250xs have an mechanical pump operated by crankcase pulses(vacuum) which feeds the electric VST pumps? electric usually fail due to lack of fuel to lube and cool the pump. I need to check my merc manual but there should be away to check that mechanical pump flow.

[arrowwaves]

Thanks guys I believe it is a restriction issue. I will be looking in that direction. Fuel pickup , line to transom , line from transom to outboard and the lift pump.

[Dd24skater]

I have seen fuel line delaminate under suction and return to what looks normal , replace all fuel supply lines and run the engine off an external fuel supply.

[arrowwaves]

I have the boat back home. the mechanic said he vaccum checked the line from tank to engine and there is no restriction, checked the voltage and said it is not a problem. The water separator/filter has rust on it and when I cut it open there is rust inside on the metal surfaces and the magnetic coil. They insist the fuel is contaminated (his gatorade bottle full of my fuel has not separated after 2 weeks) and causing the fuel pump impellors to rust and jam. The fuel filter was new on sept. 6 of this year.

[aaronmt73]

Id pull the pick-up tube out of the tank and remove the anti-siphon ball.Those can randomly stick and restrict fuel pressure,then be perfectly fine the next minute.I remove everything from the tube except the filter if it has one on the bottom.

[Superbender]

I'm hoping he didn't check the vac @idle an he took the boat out for a ride with the gauge hooked up for a accurate reading(you see what I did there)

[arrowwaves]

thanks eric, you know it was done at idle on the trailer it was the first thing I said to him.Looking into changing everything, all fuel lines and cleaning the tank.I will pump out the remaining fuel (less than 25 gals. ) just to remove it as a cause. Its Progression fuel line to the transom then about 18 in.of regular fuel line with a primer bulb.

[Tom Foley]

I have the boat back home. the mechanic said he vaccum checked the line from tank to engine and there is no restriction, checked the voltage and said it is not a problem. The water separator/filter has rust on it and when I cut it open there is rust inside on the metal surfaces and the magnetic coil. They insist the fuel is contaminated (his gatorade bottle full of my fuel has not separated after 2 weeks) and causing the fuel pump impellors to rust and jam. The fuel filter was new on sept. 6 of this year.

What a friggin SAGA !! Fuel components should be made to live in the enviro they are operating in !! This Ethanol thing didn't happen overnight !! I have over 400 collective hours on two 260 EFI platforms with no ethanol issues ..WTF .