BigBendFishing.Net

Went to Aucilla yesterday. Did pretty good...considering the circumstances. Got one red (top water..in close) 7 trout and a shark in one boat...mostly streight lininig gulp...way out in 8 feet of water. Grass want too bad...but gave us a little trouble.
Here is the circumstances....we had two boats. One ran fine all day. The other..40h Johnson ran good at first...but while going fullout...it settled out by itself...and died. Bulb was flat. Pumped it up...hit the starter...started right up. Hit the gas...got going...fast..it went a short distance....and then began to cut off. ..and then died. Nothing visably wrong. Started it up....and ran slow speed....did ok. When attempting to go fast....it died.
Limped on in...with it running..2300rpm....ran all the way to the landing...slow speed...about 3 miles.
Question.....what,s your opinion as to what is wrong? Have the intentions to replace the entire fuel line, bulb, connections. It,s about a 2003 motor..fuel filter chanced last year.. I,m baffled.

Sounds like vapor lock. I had the same thing happen on a riding lawnmower (minus the bulb part of course). I loosened the gas cap to allow air in and it went away. Turned out the breather hole in the cap was clogged.

Not sure how a boat fuel tank breathes, but I am sure there are folks here that can elaborate.

Sounds like a vent problem. The gas tank should be vented. If it's a portable tank, loosen the cap and try again. If it runs fine, replace the gas cap. If it's a built in tank, check the vent for obstructions.

It is either the valve in the bulb or trash in the fuel tank blocking the fuel pickup. I believe there is also a anti-siphon valve at the top of the fuel tank that could be the problem too.

Run the boat on a portable fuel tank with a new hose and see what happens.

I agree with Tincan, vent problem.

I do have one question, you said the bulb was flat. If it was flat, how did you get it to pump? Seems you had to vent it somehow to let the bulb fill back and expand......

Maybe you removed the cap on the tank to check it, therefore releasing the vacuum.....

And I KNOW this is stupid, but I have to ask. Some of the portable tanks have a vent you can close and open......be sure it is open.

Dubble

PFKing is probably right. Try loosening your fuel cap and see if it dies on you. The only other thing might be the high speed vents in the carb but it wouldn't just die; it would just bog down on you. good luck!

I once had a similar problem - every time I tried to get the boat on plane, the motor petered out. Turned out in my case that my fuel line was not clipped onto the gas tank and each time the front of the boat came up, the gas tank slid back just enough that it pulled the fuel line out of the tank. I felt silly, but was glad it was an easy fix.

What TC said is correct.
For a combustion engine to run you must have;
1.fuel.
2.air.
3. fire.
You need air.

WELL? Did you figure it out?