Ok I am sure this has been discussed somewhere on here, but danged if I can find it.

I have a 77 evinrude 55 hp, the other day we were out and the bulb would not prime, so we ended up sitting throug stom on shore until the trolling motor could get us home.

Anyway, I have repaced the fuel tank and the entire fuel line from take to motor including the bulb.

Now when took the boat out this morning and the NEW fuel bulb is being sucked flat. I am at a loss.

THe ONLY part not replaced is the fitting off the old tank to the new tank for attaching the fuel line, this this fitting have some sort of valve that could have gone weak or something?

BTW, when the bulb goes flat you can disconnect the line from the tank and the bulb will reinflate and you never miss a lick.

Did you buy one of the cheap wally world bulbs or a good one? The last one I bought from wally world did that. I will never buy another one from them again. I went to a marine dealer and bought a good one. Problem solved.

Is the arrow pointing towards the motor?

I actually got it all at Bass pro yesterday, a Moeller (i think) tank,and the (bass pro Brand) fuel line.

Yes it is pointed in the correct directions, points with the fuel flow to the motor

The vent is closed on the tank or is clogged.

Cajun, i think you may be right, After closer inspection the vent on this ne tank required the vent cap be almost totally unscrewed in order to fully vent. And, that would fit the symptoms we encountered this morning. I plan on making another test run this afternoon if the wind will lay just a bit.

Thanks guys, and as usual, I appreciate all the great advice.

I have a jon boat (garage kept actually). And I purchased an attwood gas tank and the fuel line for it as well. Bulb included. For whatever reason the bulb all of a sudden wouldnt stay charged and seemed flat which in turn would kill the engine unless I constantly pump it. It will re inflate just fine but when gas is flowing correctly the bulb should stay solid. If I need to buy a different gas tank and fuel line/bulb so be it. But if rather address the issue than drop $100 to replace a 1 year old fuel tank/fuel line assembly. Is moeller any better??? Thanks. Oh and if it matters it's a '93 9.9 evinrude that runs like a champ.

if its going flat, then you have a pressure issue. Definatly look for a closed or closed vent.

The gas tank does not ventilate well at all. Piss poor design, when out In The sun it blows up like a balloon. I have to open gas cap to let it deflate. Will all that buildup pressure cause these problems that I have had?

If it balloons up the tank is under pressure, if anything wouldn't that help it push fuel through the line?

Or it's possible that it's creating a vaccume and the tank is doing the opposite. If it's collapsing that would make more sence.

if the tank is becoming pressurized then you need to open the vent cap more.

If its a new style tank that the cap clicks when tightend like your truck does there is no vent it should have a fuel demand valve in the line between bulb and tank you can thank epa for this