'03 Yamaha 50 fuel problems

[torabuff]

I have an 03 Yam 50 on 19' carolina skiff bought new and have had fuel problems since. every time I throttle up from idle it begins to die, unless the fuel bulb is being squeezed at the same time. I have replaced all the fuel lines and fittings, fuel pump was replaced and the carbs were removed and cleaned by the dealer. virtually everything is new in the fuel system. The motor has been run with the gas tank cap on and off,filter in and out the pick up screensin the tank off and on and still no solution.I was hoping someone else has had experience with this, at this point I'm lost. appreciate any help

[rodbolt]

hahahaha your killing me. you answed your own post showing the ignorance. IGNORAMUS.ok. now that thast over.only thing pumping the primer does is insure the point of injection to the combustion chamber has adequate fuel. ya answered your own question

[torabuff]

Of course it is a fuel starvation problem on a perfectly sealed fuel system and perfectly ventedtank. I was thinking more of an inherent carb needle and seat problem or maybe a weak pump problem something of that technical nature.You instead showed what an IGNORAMUS you are bynot being able to discertain that type of information from my original post.

[Casco Bay Outrage]

Take it back to the dealer and press them to resolve the issue.

If they beg off, call Carolina Skiff corporate and raise a major fuss.

Regardless of what the problem, your dealer should correct it.

Let us know how this goes.

[waterbill]

Of course it is a fuel starvation problem on a perfectly sealed fuel system and perfectly ventedtank. I was thinking more of an inherent carb needle and seat problem or maybe a weak pump problem something of that technical nature.You instead showed what an IGNORAMUS you are bynot being able to discertain that type of information from my original post.

[waterbill]

One thing I would check is your fuel pickup in the tank. On a built-in tank there should be an anti-siphon valve where the fuel line starts. This is a little check ball which may be partly stuck closed, restricting fuel flow. That could explain why at low RPMs there is sufficient flow, but not at higher fuel demands, i.e. higher RPMs. Try using a portable tank and see if the problem disappears. If it does, remove and cean up that valve. Please let me know what you find.

[overthere]

yea ok rodbolt answers not b.s. comments huh. Take off the fuel lines leaving going to the carbs from the fuel pump. (make sure you disconnect the spark plug wires you dont want it to start) If you have a good pressure then rebuild the carbs. Or have someone better do it. I belive there is 4 carbs on that motor each cylinder has its own. They could have rebuilt two on ya or something said the others arent dirty. By testing the fuel pump at least you will iliminate everything up till that point. Another way to test on that motor is by removing one spark plug at a time while running at a idle. Listen to the motor for a miss if removing a plug from a particular cylinder doesnt make a difference then you know the problem is past the fuel system and most likley on that cylinder. Thats how I did it on mine at least I had the same exact problem. Good luck let me know how it turns out.

[rodbolt]

yall are killing me.
lets look at the info given, idle appears ok , problem occurs on acceleration and can be eliminated by squeezing the manual pump.
that pretty much eliminates the carbs. attach a fuel vacum guage(available at any parts store and most wal marts for about 16 dollars) to the pump inlet . fuel system vacum should never rise above about 4" Hg. if it does look for restrictions, it should also stay about 1/2 to 1"Hg.
if it does not there may be an air leak.
you can also attach a known good clean portable tank directly to the pump inlet.
make sure the oring on the engine filter is not missing.
sorry if I sounded gruff, was having a bad night .
but anytime your trouble shooting the systems its a process of what works and what does not then look for which part or subsystems is missing.
no sense in calling carolina skiff as they dont have any affiliation with yamaha.
has this engine done this since it was new? and if it has was it documented with the dealership ?

[overthere]

When you put pressure on the fuel ball it will fill up the bowls in the carbs there are some small ports inside the carb going to the fuel bowl that clogged on mine. Id like to hear how it turns out so i kow if it happens on mine.