Fuel Problem (Collapsing primer bulb)

BoniB · #1 07-26-2010, 11:59 AM

Kept having this problem Saturday. Engine would be running fine then just die; checked the primer bulb and found it collapsed. Got it firm and ran some more; as i felt the bulb go soft the engine would bog down ....when I pumped it the engine would start running better.

I suspect a restriction in the fuel line upstream of the bulb. The fuel filter is only a week old. I disconnected the fuel line going into the filter/ water separator and blew back towards the tank. Seemed like at first I felt a restriction but thought that may be the fuel in the line. After a second or two there was no resistance blowing towards the tank. Reconnected everything and ran the boat for about 20 minutes with no problem.

Any advice?

Thanks,
John

JohnB · #2 07-26-2010, 12:36 PM

anti siphon valve in the gas tank. it is usually located on the end of the pickup tube in the gas tank. With most gas tanks, you can unscrew the fuel tube, and pull it out. If it isn't the filter, it is usually this. You see a lot of these with alcohol gas, as it loosens all the crude in the gas tank, it will plug this. It is a little check valve with a spring. I usually take mine out sinse my gas lines all run above the top of the tank, and won't siphon.

Fr. Frank · #3 07-26-2010, 05:21 PM

What John said

apneadreams · #4 07-26-2010, 08:30 PM

Check your vent line as well...If there is blockage, it will have the same affect.

shana · #5 07-26-2010, 08:35 PM

had same problem check elbow on top of tank punch out value mine had crap at high speed gas cant get through fast enough problem gone george

McGillicuddy · #6 07-26-2010, 09:27 PM

I had similar problem. Found silicone chunks clogging the elbow at the tank. A previous owner must have used silicone as gasket material on sending unit and it eventually broke loose to bring me a bit of grief...

BoniB · #7 07-27-2010, 11:28 AM

Thanks for the advice guys.
I quickly looked under the console for the round fuel tank access hatch but do not see anything. Did the 1974 20SF have an access to the fuel pickup??
My batteries are installed under the console so tonight I plan on taking a better look...maybe its under the batteries??

I'll let you know what I find.

Thanks again.
John

McGillicuddy · #8 07-27-2010, 11:42 AM

I would think the fuel pick-up would be at the aft end of the tank. You may be able to access the fitting through the starboard stern locker if the bilge is visible, not sure about the SF layout...

ReelToy · #9 07-27-2010, 12:57 PM

Another suspect is gray fuel hose ethanol has been breaking down hose and it separates inside and inner liner collapses. Good luck