Anti siphon valve issue?

[panga18]

Boat runs fine when connected to 6 gallon external tank. when I attached the fuel line to the newly installed pemanent tank located under the C.C. of a 1973 Mako, I am not able to draw gas out of the tank. I spliced the fuel line and attached the bulb before the water/fuel seperator and still no luck drawing gas out of the line. Any thoughts? Extremely frustrated after just reinstalling the C.C. and T-top back over my gas tank.

 

[seabob4]

Re: Anti siphon valve issue?

Yank that A/S barb off your tank pick-up and install a straight barb ($4, Sierra, Worst Marine), that will solve your problem.

The spring that holds the ball in place during normal flow weakens over time, and allows the ball to move backwards, effectively blocking off fuel flow. A/S barbs are only required on I/Bs and I/Os where the fuel delivery point to the engine is lower than the fuel exiting the tank. O/Bs don't need them, but tank manufacturers ship them with the tank because they don't know what application the tank will be used in...

 

[panga18]

Re: Anti siphon valve issue?

thanks for the insight, didn't want to do anymore unneccessary work. I've done plenty so far but am learning.

 

[seabob4]

Re: Anti siphon valve issue?

Learning is a VERY good thing...

 

[panga18]

Re: Anti siphon valve issue?

while I'm at it, could it have anything to do with my vent line? Its a poly tank and I would assume it has enough flex to it that I would have gotten some gas before the suction stopped the flow correct? I got nothing.

 

[seabob4]

Re: Anti siphon valve issue?

Check your vent line for any kinks, especially by the fuel inspection pie where your vent should make a loop. Vent line runs up the hullside, then back down to the vent. Over time, the walls of the vent hose can collapse, causing a kink...

 

[Bob's Garage]

Re: Anti siphon valve issue?

This may seem far fetched, but the OP didn't indicate that there was a vacuum being produced when he pumped the bulb, so I wonder if he may have put the vent on the wrong barb?