1997 SN GT-40 Stalling - need advice

[TimS]

I’venever posted anything in the past and I’m an amateur mechanic at best but Iseem to have run out of repair options and my problem persists so I thought Iwould turn to others for help. I have a 1997 Ski Nautique that was bought newfrom the same dealer that has serviced it from the outset. Beginning twosummers ago, I began to have various fuel related issues and I’ve done thefollowing:
- replacedthe relays (intermittent stalling and problem corrected)
- hadthe fuel tank drained and the lines cleaned (stalling after a few hours of usewhich was diagnosed as a clogged screen in the fuel pick up at the tank)
- replacedboth fuel pumps (as a result of my current problem)
Mycurrent problem began mid-summer last year. The boat was used for a few hourswhile skiing without an issue. After an hour or two at the dock, I went backout at idle speed and made it about a ¼ mile before stalling. A few hourslater, the boat started and ran without an issue. A couple weeks later, samescenario (skiing, back to the dock then back out) but this time I was at 20-25mph, but again made it about a ¼ mile before stalling. The stalling was aresult of lack of fuel rather than an abrupt stall. This time, I lifted theengine cover for 10 minutes after which the boat started and ran fine. I couldhear the fuel pump in the fuel cell turn on each time. The same scenario hasnow occurred 6 times but lifting the engine cover for 5-10 minutes allows theboat to again start and run fine. Not sure what else it could be. Your commentand suggestions would be invaluable

[surroundsound64]

Check the fuel vent?

Once you verify that the vent is clear it seems like you'll be able to dismiss the fuel system.

However, being able to lift the engine cover and the problem quickly resolve would be an indication of a temp problem. Many ignition components can breaks over time and especially when subjected to years and years of heat cycles. Try replacing you're ignition coil. Maybe some other guys will chime in who are more familiar with the GT-40.

[surroundsound64]

Now that I think about it, you may have a coil pack... Either way, I would be looking ignition.

[DanielC]

YOU MUST KNOW THE FUEL PRESSURE WHEN YOU HAVE ENGINE PROBLEMS WITH A GT-40! Yes, I meant to yell. I cannot stress how important this is.

The GT-40 does not have any feedback on what the air fuel ratio actually is. The engine's computer just assumes the fuel pressure is correct.

This is how you check the fuel pressure.
http://www.planetnautique.com/vb3/sh...=fuel+pressure

[wskiboy]

I have the same issue .I drain the fuel in a glass jar, fill it back up with fuel pumps and it starts right away.It seems to me that the fuel gets to hot in the canister .Solving this issue would great ,so please you smart fellas chime in.Thanks

[east tx skier]

Fuel pressure is certainly key. But if you have replaced the relays and you are having intermittent stalling issues such as boat starts, idles, takes off, stalls. Wait a bit, start it up, repeat scenario, check the antisiphon valve on top of the fuel tank. I have had two get gummed up in the past four years and cause just this scenario. Ethanol blended fuels tend to cause sticky ASVs over time. $11 part and easy DIY swap.

But, fuel pressure ....

[vonzipper]

Before you do anything check the cutoff switch, i bypassed mine and it cured a ton of problems, I ordered a new one from our wonderful sponsor and had it in a few days

Cheers

Scott

[slob02]

Some have a fuse coming from the battery that I "think" may cause problems with the fuel pumps. Check the relays again too!!

[TimS]

is the anti siphon the same as the air vent on the tank? The vent near the fill line? Or is the anti siphon something else? Hopefully try and tackle some of the suggestions this weekend.

[wskiboy]

on the vent line from the tank their is a stainless screen that can and does get clogged it is not easy to get at .Let me know and keep me posted . Their is also a screen in on the fuel pump ,not the one in the canister.Good luck

[TimS]

thanks for the suggestion....so the anti siphon is different than the vent line? Is the anti siphon on the fuel line from the tank?

[JayG80]

Different than vent.

Generally - the fuel supply line coming out of the top of the tank will have a 90 degree elbow fitting kind of like this http://www.skidim.com/prodinfo.asp?number=R024017. This line goes up to your fuel pump and many times has red tape on it at the end.

The anti siphon valve (ASV) screws into it and looks like this http://www.boatersplus.com/moeller-b...Fa7m7Aodr3QAgQ

There are numerous sizes of ASV - I just picked a random size off the web. The ASV has a spring and a ball bearing inside it that can gum up. Sometimes a good shot of carb cleaner will take care of it.

[TimS]

thanks...I'll tackle this tomorrow and let you know.

[TimS]

called a marine parts distributor and asked for a coil and ASV. I explained the symptoms and was told it's very rare for the coil to fail and the ASV can simply be cleaned. I was told that the symptoms were more than likely due to a worn stator. I first checked the tank vent which was clear. I checked the ASV which was very clean. I then checked the stator and although I couldn't get the distributor completely apart, it was clear that the stator was worn. It showed signs of melting and looked damaged. I had a mechanic disassemble the distributor and install the new stator. He said the stator was "toast". Planning to reinstall the distributor on Saturday. Keeping my fingers crossed.

[pSchwade]

If that doesnt fix the problem check the 60 amp breaker - mine was going out and would short for fractions of a second (but not completely trip) when it got hot.