Help!! Take the 93' Pro-Boss Challenge

[pdxCC]

Hey guys. I really need your help.

I have a 93' Ski Nautique with the 5.7L Pro-Boss 351w. All original with the protec ignition.

Last year she ran REALLY strong. This year she started right up after de-winterizing and at the dock everything was good to go.

I idled out to warm her up, then gave her the go-gittr juice and she died at about 1500rpm. I re-started and tried it again about 10 times. Same result.

I opened up the fuel/water separator and drained it, added fresh gas, same result. I also pulled the spark arester and the accel jets aremkicking in strong when I give it gas in neutral. It also revs up just fine in neutral.

No matter what, when it dies it completely dies, I can't save it no matter what. It goes from 1500 to zero rpm.

Here's some info:
-- I stored it with 1/4 tank of gas with ethanol treatment.
-- this was the first time out this year.
-- Last year it ran great so I am thinking it is a corrosion issue.
-- No idea when the fuel pump was changed.

So what does the crew think it is??

I have three thoughts in my order of WTF I think it is.
-- Fuel pump.
-- Ignition Coil/cap& rotor
-- Time for the new ignition.
-- carb service time

[east tx skier]

Just a guess, but I'd bet a shiny nickle it's a plugged up anti-siphon valve. My 98 with the GT-40 did the same thing at the end of the 09 season. $11 fix and good as new.

[pdxCC]

Where the heck is that valve?

[pdxCC]

Ok. Currently planning to replace the fuel filter and replace the siphon. Any other thoughts??

[east tx skier]

Where the heck is that valve?

On top of the tank connected to the fuel line.

[pdxCC]

Well - the siphon valve looks to be in great shape. The screen on the valve was all clear. Nix that one.

I also tore down the hard line between the mech fuel pump and the carb. The line was clear, but the screen at the connection to the carb was 80% obstructed with a thick layer of yellowish material. I assume this is residue from the tank thanks to the ethanol fuels....

So if the screen was blocked do I need to tear down my carb and clean the jets? Any other concerns you can think of???? I am trying to find a fuel/water separator cartridge locally so I don't have to wait all week for one to arrive by mail...

Cheers!
Brett

[surroundsound64]

Run some marvel mystery oil through it. Should help clean it up some.

[horkn]

Just a guess, but I'd bet a shiny nickle it's a plugged up anti-siphon valve. My 98 with the GT-40 did the same thing at the end of the 09 season. $11 fix and good as new.

That would be my guess. but I see you said it was not that. The AS valve can be cleaned and does not need to be replaced fwiw.

The e10 may have cleaned your fuel tank, but the debris is probably getting caught in a filter/ screen after the AS valve. Seeing you said the inlet screen to the carb was 80% blocked, I think you found the culprit.

I wouldn't blame the ethanol for cleaning your fuel tank of gunk that coated the tank from impurities or old gas from the almost 20 years the boat has been around. The ethanol cleaned your tank, now you just need to clean up after the 20 years of crud that accumulated.

[pdxCC]

I hope that is the case. I am going to get the new filter and then flush my fuel lines. Keepmthe proverbial fingers crossed.

[pdxCC]

Solved. Screen at carb was the deal. I am also running starbrite and marine sta-bil through the tank.

Back to running strong for another year!!

Cheers & Thanks!
Brett

[horkn]

I'm very happy that you fixed the problem for little cost and hassle.

To keep the gas stations built up crud from their tanks entering your fuel system, I would only buy gas from the newest tanks / stations and the ones that see he most use you can find. This crud issue will be solved quickly once the ethanol has cleaned all the fuel tanks and enough filters and screens get cleaned and replaced. We've been running ethanol for 20 years now in WI, and we had some issues at first. Those days of blaming e10 are gone except for the ignorant people that want to blame whatever they don't understand. I've not had one engine burn down in all my years of ethanol use. That includes 2 and 4 strokes, from weed wackers to v8 car motors.

As a side question,
I know in pdx and all of OR, that you can't pump your own gas. Is that true with boats and bikes too?

Also, it's a 5.8 liter, or a 351W, because a 5.7 350 is a GM moniker.