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Fuel supply problem

J

John Casteen

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"I have a 15 hp Evinrude, 1975

"I have a 15 hp Evinrude, 1975 model, that has been running great thanks in part to the help I've gotten from this board. I'm having trouble getting gas to it, and wonder if you could point me in the right direction.

Last weekend I lost pressure in the primer bulb in the fuel line, and the motor will no longer run at more than about half speed. The rpm drop began as soon as the pressure loss started. I've replaced the bulb (though the old one turned out to be fine) and checked all components of the fuel line. Nothing's clogged (it's 5/16" tubing) and I don't see any cracks or holes. All connections are clamped with hose clamps, and the components are all a year or so old.

Any ideas? Thanks in advance.

John"
 
john do you have an air bubble

john do you have an air bubble in the line. try to push down on the ball valve lightly and hold in up so if there is air it will come up to the surface and have someone squeeze the primer bulb slowly on you have fuel come out remove whatever you are holding in the ball valve with. fuel line should be bleed of all air.
 
There should be a screen filte

There should be a screen filter on the end of the pick up line inside the fuel tank. This could be clogged (I assume that you are using the portable type tank) This is usually accesable by unscrewing the fitting from the tank and withdrawing the pick up line and filter along with the fitting all in one piece. Clean any crud from the filter and check for possible holes in the pick up line .
Hope this helps.
 
"Thanks for both of these sugg

"Thanks for both of these suggestions. I'm going to try bleeding the line of air, and have already checked for a clogged intake tube (it was clear). And, yes, it's a portable tank.

Am I right in thinking a pressure problem in the line would limit the wot rpms? The motor runs smooth and consistent, so I don't think it's the fuel pump, and the rpm drop happened exactly when the primer bulb went limp. I was underway at the time-- the engine stalled, and I was able to restart it with the limp bulb but haven't gotten it to run since at more than about half throttle.

John"
 
only thing else I can think of

only thing else I can think of at this time is a faulty o-ring in the quick connect at the tank letting air into the line. You might try removing the quick connect and inserting the open ended hose directly into the fuel just to be positive that your connector is not the problem.
 
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