fuel pump problem?

[Brento311]

I went camping this weekend, and ran my little Evinrude 9.5 Sportwin all weekend. The more it ran, the better it did. It got to where it would idle fine, and run much smoother. All was well until it was time to leave. On the ride home, wide open it would do half what it normally does. The motor missed and sputtered like it was going to die. I could pull out the choke, push it back in, and the motor would momentarily run pretty good again. I squeezed the primer bulb, and it was limp, but squeezing had no effect. The friend that I bought the motor from put a new fuel pump on a year or two ago. Could someone please tell me what this problem is? Thanks<br /><br />Brent

 

[dragonslayer]

Re: fuel pump problem?

Hi Brent,<br /><br />If the motor ran better after activating the choke, that would indicate a lean condition.<br /><br />Sounds like you should check for a partially clogged high speed jet.

 

[rolmops]

Re: fuel pump problem?

Hello.It could be that you were almost out of fuel and the fuel line sucked air instead of fuel.Or you have a leak in your fuel line which causes it to loose pressure.It does not sound like pump trouble.<br />Good luck.

 

[Brento311]

Re: fuel pump problem?

Hey, I know I wasn't out of gas because I had over half a tank left in my 6 gallon tank. How do I check that jet that you mentioned, dragonslayer? Thanks<br /><br />Brent

 

[dragonslayer]

Re: fuel pump problem?

On the front of the carb at the bottom is a 7/16 bolt head that has a straight head screwdriver slot through it. This is the bowl drain. Inside the carb behind that is the main jet. <br /><br />The jet has a slot in it and unthreads counter-clockwise from the bowl. It's much easier to get it out with an orifice tool but can be done carefully with the right narrow screwdriver.

 

[Brento311]

Re: fuel pump problem?

I read a previous post where someone had the same trouble with their motor as I am having with mine. The problem ended up to be a torn fuel pump diaphram. Could this be the problem? Where is the fuel pump diaphram? THanks<br /><br />Brent

 

[dragonslayer]

Re: fuel pump problem?

When the fuel pump diaphram is bad the fuel pump usually will not pump fuel. By squeezing the primer bulb the motor picks up and runs normal because you are becoming the fuel pump and filling the carb.<br /><br />The other thing I have seen with a bad diaphram is fuel gets through the diaphram and into the engine through the pulse line. This causes a rich condition on the cylinder that supplies the pulse for the pump. Because it's rich, pulling the choke would not make it run better.

 

[granpafish]

Re: fuel pump problem?

Rolmops hit on a possibility that you ought to try right out of the gate. The symtoms point toward possibly a leak somewhere in the fuel line. Go buy a new fuel line (with bulb) and try that. Cheap, fast, and if it isn't the answer, somrthing that you ought to replace every so often anyhow. Good luck

 

[rogerwa]

Re: fuel pump problem?

I think the key is that the bulb was limp. Does that mean sucked flat?? If so, check for a clogged fuel pickup. Pumping the bulb will help an air leak. I am betting on a faulty bulb or clogged fuel pickup..