gas issues

[jsylvester08]

So I finally got the boat out this past weekend but of course I ran into some issues. The issue I am having is that I can use the fuel bulb to prime the engine but when I get the motor up and running the bulb collapsed and the engine studdered and died. I could pump gas back into the bulb but the same issue would occur. I replaced the fuel bulb because I thought that it was the anti-siphone was stuck. Could I hve something in my tank that would be clogging when the engine is trying to suck gas? Where would this be? Can I access it from outside the tank? its a coffin tank in the floor and without taking off the consol and floor I cn only access where the hoses connect to the tank, through a port hold. Also at the end of last sean I left gas cover off and it ws sitting in the yard for a week. I siphoned out all the gas and any debris I tought was in there. Do you guys have any ideas of how I could get in and clean my lines?

[wingtime]

If there is a anti syphon valve it is located in the hose barb ON the fuel tank.

[Blue Agave]

Make sure the vent is not clogged / corroded.

[jsylvester08]

The vent to my knowledge is clear when I fill it I always feel for the air rushing out and this weekend was the same good amount of air flowing out. What does the fuel barb look like where it would connect to the tank? is it like the fuel hook up to the motor that has 2 female holes( not quite sure how to describe it.) but its the hook up to like all on deck tanks.

[dburr]

http://www.classicaquasport.com/phpbb3/viewtopic.php?f=2&t=10604&hilit=Anti+siphon&start=15

This should take you to a post that has a picture of what you are looking for.. Your tank fitting may not have the shut off that this one does..

A little more info on what you have in the fuel system would help too.. You mentioned a new primer bulb, how is the filter if you have one?
 

[Georgie]

As the guys have said, the anti-siphon is probably the culprit if your vent is clear.  If the bulb is collapsing your fuel pump is strong b/c it's creating enough of a vacuum to collapse the bulb.  The problem is simply the lack of input from the tank to re-fill the bulb.  The only other possible issue I can fathom would be some sort of mystery clog in the lines somewhere between the pickup and the fuel bulb.  Perhaps a bad fuel filter or water separator?

[redemn93]

im having the same issue but my problem is the water seperator.  apparently i shouldve cleaned my tank when putting the boat together     im an idiot for not doing so.  the seperator gets filled with crap, looks like roach exo-skeletons (boat sat stripped and empty for a couple years before i got it), every 15-20 minutes of high speed cruising.  needless to say im getting the tank flushed in the next week or 2 before family comes in for vacation.  

check your seperator, pour it into a clear container and let it sit.  even if you dont see debris, let it sit.  see what seperates after a few minutes.  let us know.  go ahead and change the small filter on the motor.  cheap enough and good maintanance anyway.

[jsylvester08]

So I put an hour into trying to get to the anti-siphon valve. I was not able to in screw the gas pick up from the tank because of the angle I was trying. I think I might need to pull the console and also the coffin cover. But so here is my progress. I pulled something that looked like a nut shell from my gas line when I pulled it off the connection. I'm not sure if this was what was clogging my line but I'm wondering is the  anti-siphon valve in the fuel pick up which goes down into the tank? Does anyone have any tricks to unscrew it? Could it be welded to the tank? I don't want to create more damage then there already is.

[Georgie]

some sort of mystery clog in the lines somewhere between the pickup and the fuel bulb

Looks like you might've found it!  

If you've already removed the hose from the barbed fitting, then perhaps just make sure you can blow air without obstruction from the tank end of your hose to your bulb.  If so, then I'd reattach the hose to the fitting and try to run it before you tear anything else apart, just in case the shell turns out to be the entire problem.  Fingers crossed that's all it is.

[redemn93]

very well could be the issue.  good find if so.

[jsylvester08]

So the problems continue. I thought I had figured out the problem but I noticed that a pattern has shown. When I first get the motor going it will get up and run for about 5-10 min. Without a problem then it gets choked and runs of of gas. So can anyone help. If it runs for 5-10 min then it is deff sucking gas from the pickup on its own but then at some point why does it stop picking up? Does this mean the anti-siphone valve slowly gets stuck? How can I get to the valve if I can not unscrew the pickup from the tank.
Thanks for everyone's help

[hogdogs]

That sounds like a venting issue....
Or a bad bulb???
Brent

[fitz73222]

Hey Brent,
Run it with gas gap off and see if the starvation goes away. It it runs fine, you have a vent issue. If it runs the same, you have a gas delivery issue and look towards the anti siphon valve being the culprit. Easy fix. Unscrew the entire fuel connector block from on top of the tank. Screw in a new brass elbow and screw your existing fuel barb back in. Make sure all the pipe connections are sealed with 2A Permatex sealer; done. If that doesn't work let us know.

[dbiscayne]

Theres only a few things it could be, most have been mentioned already but theres another.  
Fuel lines sometimes deteriorate from the inside out, they have an inner liner that'll separate, get mushy, and collapse under the suction of the fuel pump.  Can't see it happening and the hose can look fine from the outside.
Have you tried placing a short length of new hose on the tank pickup and blowing into it?  At least that'll narrow it down some, if you can't blow into the tank with reasonable pressure (should be able to just blow through the hose with your mouth) you've got a stuck check valve.
Then try blowing through all the fuel lines from the tank to the filter, and filter to primer ball, after disconnecting them.  Do this last so you don't have that taste in your mouth for too long.  The hose from your primer ball to fuel pump/engine must be OK otherwise the ball wouldn't be sucking shut.

[redemn93]

like i mention in my earlier post, i had a similar issue.  mine turned out to be the antisiphon valve on the tank.  i removed it just to see and it was totally clogged.  looked like it sat without a fuel like for a while in the past and mud dobbers filled it in to make a nest.  spring and ball were missing too.  replaced it and went out yesterday for a good 20 mile test run.  no issues.  ran great.  it would have caved the primer bulb several times in that length of travel before.