Fuel bullb is collapsed

[verne1972]

Ok this is my first post and I will try to convey the problem as accuratly as possible... I have recently purchased a 77 Evinrude on a 77 Aquasport center console. When i first took the boat out and opened the thottle all the way up, the primer bulb would suck flat and starve out the engine. So i went home, replaced the bulb, fuel line and checked the vents for blockages... Went back to the water and the engine ran great with no problems for over an hour, so i thought the problem was over... So yesterday i decided to take my wife out so she could have some justifcation why i spend so much time outside with this boat... And you guessed it, primer bulb suck flat at 3500 RPM's. Removed the inline filter and nothing changed... Removed the primer and nothing changed (suck the line flat).

What the heck is going on???
I have replaced the line (3/8), filter, bulb, vent and checked the pick up for a filter (does not have one, it is a 5/8" alum. rod strait down in the tank with a half moon cut out on the bottom).

PLEASE HELP!!!! What do i need to check that i havent????

 

[verne1972]

Re: Fuel bullb is collapsed

Sorry, the Evinrude is a 115..

 

[DJ]

Re: Fuel bullb is collapsed

There is a valve on the outlet of the fuel tank called an "anti siphon valve". It is a one-way check ball. They can and will stick.

The valve usually has a hose barb on one end and screws into the tank, on the other. They can be removed for testing but I suggest you replace it. They are cheap.

 

[verne1972]

Re: Fuel bullb is collapsed

thanks, would that check valve ball be on the in the fuel pick up rod??

 

[ezeke]

Re: Fuel bullb is collapsed

The hose is connected to an outlet fitting at the top of the tank. The anti-siphon valve is inside the fitting. It usually consists of a ball bearing and spring.

 

[Silvertip]

Re: Fuel bullb is collapsed

The antisiphon valve is the fitting to which the fuel hose connects at the tank. It can be unscrewed from the tank and cleaned or simply replaced. You might also remove the entire fuel pickup tube as gunk in the tank may, and very likely is clogging the pickup screen. Or, when you have the antisiphon valve removed blow air through the pickup tube to clear the screen. It may not stay clear long, but with a clean antisiphon valve you will quickly know where the issue lies.

 

[iwombat]

Re: Fuel bullb is collapsed

Let's try the easy stuff first though. Is the tank properly vented? When fuel goes out, air has to go in.

Reread the post. Looks like you checked the vent already.

 

[floatingwoody2006]

Re: Fuel bullb is collapsed

When this happened to me, the hose was reversed.

 

[tashasdaddy]

Re: Fuel bullb is collapsed

yep that would do it. arrow on bulb pointing to the motor.

 

[verne1972]

Re: Fuel bullb is collapsed

thanks for the post. i am willing to bet its the check valve in the pick-up. unfortuantly, ive spent the last four days working on the boat, and SHE says if i go out there today, im sleeping with it tonight. So ill check it tomarrow, and repost... Thanks again...