1994 150 evinrude fuel issues

[pwt413]

Finally got the boat on the water this season. 1994 Stratos 285 pro xl. The first time I went to put it on plane, the power wasn't there. Continued slowly a bit, put it in neutral and revved it some. Tried to get on plane once again, and this time it worked. Then when I slow back down to a crawl, and eventually the motor dies. Didn't think much of it until I went to start it up again a while later. Wouldn't start. Figured it wasn't getting fuel, so went to prime it again, and it started right up. Went back on plane fine, then off plane to a crawl, and it died out again. So it was over and over like this all day.

Hoping I don't need a carb rebuild, don't know how to diagnose that. Could there just be an obstruction in the fuel line? The boat has 2 tanks, and I believe one is empty. Could that be causing some sort of vacuum problem (not sure if that makes sense)? I couldn't prime it without switching solely to the tank that had gas. I thought I usually just run it with the tank selector in the middle position (i.e. both tanks). Any ideas would be greatly appreciated.

[Lockjaw]

If it sat all winter, it probably has gummed up carbs. I never go out without seafoam in mine for the first trip.

[noelm]

probably first off, best to try a complete remote tank and hose, before anything else is done, that way you will know for sure if you have a tank/fuel supply problem

[ELGIN]

Was the boat winterized?
With fuel conditioner?

[Lockjaw]

I am betting no.

[pwt413]

It was winterized, I'm not that bad. Change oil, stabilizer in the gas, fogged and sprayed the whole thing. Put in new plugs this spring.

I just had it running out in the backyard after filling up the tanks and putting a pint of seafoam in each tank. Started fine, stayed running at idle. Revved it up a few times, and it settled back into idle fine. Turned it off and waited 10 minutes or so, and it started and held idle fine. I guess one more trial at the lake is in order.

[Lockjaw]

Flog the chit out of it.

[Lockjaw]

Are the plugs gapped properly? Make sure you got the wires on the plug tips good too.

Also, one of the things that caused me considerable grief was the fuel filter cap. If its not on tight, or if the little gasket is leaking, it will cause you to have issues getting on plane. Make sure the filter isn't nasty too.

I freakin hate that stinking cap.

SEAFOAM

[ELGIN]

Have you checked the fuel system for oil?

The oil tank is vented to allow air in but not to let pressure out, if the oil tank pressured up while stored the fuel system will be full of oil.

Remove the air box and have a container ready to catch the fuel/oil, pull the top carb bowl drain plug and see what you get.

[pwt413]

OK, this response should provide some chuckles to the more knowledgeable...

As far as the plugs, I just stuck in what I believe are the recommended plugs, and what was there before. Didn't alter the stock gap.

Regarding the fuel filter cap.... fuel filter cap?

Regarding the oil tank... I know there's a tank, and oil goes in it. I've checked the oil level lately. I suppose that would relieve any pressure?

This is beyond my knowledge of the boat: Remove the air box and have a container ready to catch the fuel/oil, pull the top carb bowl drain plug and see what you get.

Thanks for everyone's help. Bear with me.

[Lockjaw]

You need to gap the plugs properly at 30 thousandths. Normally they are gapped to close, sometimes though, to wide.

For the rest. Take the cover off the motor. There is a black box on the front of the carbs. It has 4 rubber straps that hold it in place. Pull the straps loose. and the front cover should come off the carbs. It has 2 hoses that connect to it, so pay attention to their placement.

If you see a bunch of oil come out, post that. If you see a bunch of fuel every where, post that. On one of the top 2 carbs, remove the largerst brass screw you see, it uses a flat head screw driver, and report in what comes out, especially if not gas.

The fuel filter cap should be white, you will see it in the center of the engine. The fuel line connects to it. Make sure it is good and snug tight.

If you can fire the engine up outside, then do so with the cover off the carbs and see if you see any leaks.

[oakhillhoss]

If'n You'n got 2 Tanks and 1 is Empty why would you run with the Switch on Both Tanks. Now I may be wrong but I would Swear I just read that in this Post. Been Drinking Water so I may be under an Influence.

[FirstGear]

I changed plugs and it ran like crap. I put the old ones back in and it was good to go. Put your old plugs back in and see if that makes a difference. Hope you still have them.
Good Luck

[pwt413]

I have been busy with trailer problems, but made it out once on the water, and the motor seemed to hold idle fine, and take off well too. Haven't had time to perform all the diagnostics suggested, but thanks for all the input.