Fuel bulb is collapsing

[Deleted]

Looking to buy a 95' 210CC , owner told me he has a problem with the primer bulb collapsing during full throttle. Any ideas what the problem could be, or is this a problem  that I should walk out on the deal over.

[floundereater]

Filter is probably clogged. Anti siphon valve bad. I wouldn't think it is a big deal at all

[seagristle]

Had same problem on a 2002 2100. Bad anti-siphon valve. Broke trying to get it off had to replace the whole pickup tube. Did NOT put another ASV in.

[freezerfiller]

This can also be a stuck check valve in the bulb as well. But because it only happens at full throttle, my money is on the clogged fuel filter, fuel tank vent, or fuel pickup tube.

[985crabs]

Happened to me and it was the vent in the fuel tank fill cover being stuck closed.

[acdaddy0]

Yeah that's not a deal breaker, just a problem that he didn't know how to fix! It's one of the above mentioned, definitely a restriction in fuel pickup prior to motor. Check fuel tank vent for blockage. Have had bees or mud dobbers build nests in small orifices. Not sure if there is a screen on the pickup in tank or not? Anyone? But I would run a new fuel line and replace primer bulb first. Rubber fuel hoses degrade and collapse or there maybe a kink in it that only effects flow when motor is at full throttle.

[deke]

New to forum, SeaPro 180cc(1998) owner. Purchased in May 2015, very happy with it and no issues until recently. Same primer bulb collapsing issue. Replaced filter, fuel lines, and bulb. Still having new bulb collapsing issue at full throttle. Vent mounted below fill cap appears to be clear, but don't know how it's attached or how to test it. Not sure what a anti-siphon valve is or where can I find it. While running, I've found that if I back off on the filter and allow air to be drawn in, the vaccuum on the bulb is released and I'm able to run about half throttle. So, I think my problem is the same as some here have posted. Only quazi-mechanical so can someone talk me through the steps?

[Juan]

Welcome aboard deke. I know you said you changed the fuel filter but are you sure you only have one filter? There is probably one on the engine and you could possibly have a fuel / water separator filter somewhere too. If either or both were blocked, it could cause the primer bulb to collapse under a load. If that's not the problem then as already stated in this thread, your anti siphon valve could be the problem. It's located on your fuel tank on top of the fuel pick up tube. I'm not sure about your model, but most models have an inspection plate that allows you access to the fuel tank and the fuel gauge and pick up tube.

Anti siphon valves explained

[deke]

Thanks Juan!  Didn't think about the filter on the motor, since it was downstream of the bulb, but I'll look at it. Actually, I have a fuel/water separator mounted near the stern.  I referred to it as the filter, and it's what I've been loosening to allow air in to release the vacuum on the bulb. I don't think I have another filter.  Can't see anything through the hatch for the battery and bilge pump.  The only other access port covers are high on the gunnel walls.  One is below the fuel fill cap on the starboard side, the other is immediately across on the port side.  Info on the anti-syphon valve is a big help, however, there are no access ports in the floor deck save the battery hatch at the stern.  Two small conduit pipes come up inside the center console for the teleflex and control wiring, so I'm confused on how to check at the tank.

[gnrphil]

Is there a round inspection plate in the floor of the console ?

[deke]

If it's there, I've overlooked it.  Probably going to wait a few days until the temps here get above freezing before I can check.

Thanks!

[mcsd63]

There has to be an inspection plate. There would be no way to replace fuel lines if there wasn't. As mentioned earlier, it may be in the floor of the console.

[freezerfiller]

I think you are on the right track if you loosened the filter than your problem is either the filter, or upstream of that (fuel vent or more likely the anti siphon valve. next time you experience the issue, loosen the gas fill cap. If the problem goes away, it's your fuel tank vent, if not, it is either your ASV or the pickup is clogged. The ASV is in the brass elbow where the fuel line clamps onto the tank. I threw mine as far as I could throw it, but if your fuel line goes below the top of the tank it could be USCG required, so you might need to replace it if it could possibly siphon your tank out.

[vlaw45]

Hi, if anyone could post a picture of exactly where the fuel pick up enters the tank on a 180cc it would help me a ton. I opened the access panel in the center console and only saw the fuel gauge sending unit. Thanks, Vic

[freezerfiller]

Mine is right there beside the sender.. Just look for the brass barb and the fuel line.

[deke]

With everyone's help and advice, the diagnosis is the ASV causing the bulb to collapse. Much appreciated! I've limped along all summer just running half speed, putting off replacing it, until today. Need help with knowing what to expect. Got the cover plate inside the center console off and it gives you a good look at the sender. The ASV on her is aluminum, not brass as expected, It's about 2" stern of the edge of the access hole, which puts it under the back wall of the center console, so cutting the floor is a non-starter. No one told me you need to be a contortionist to do this, but I managed to get the fuel line off, and screw the ASV out. Now I need help. I can flex the pickup tube attached to the ASV, but there's only about 4" clearance to the bottom of the deck, so since it's about 7"long, your not going to get it straight out. I'm guessing there's a filter screen attached to the bottom of the pick up tube, because I get a hard stop trying to pull the tube completely out. I'm beginning to understand why Seagristle didn't want to put another one back in. The fuel line runs above the tank to a stern mounted nipple. I can't see how she'd syphon fuel, when all the lines are above the tank. So, back to the fix...if I jerk the tube out, can I expect to leave a filter screen in the tank? Is there a trick to this? I'm stuck.

[Juan]

If the entire fuel line is completely above your fuel tank, it will probably never siphon fuel without without an anti-siphon valve but they're there for a purpose and I've read somewhere that they are required by law in the U.S. If it were me, I'd replace it to be on the safe side. There is a screen on the end of the tube but I would think that if it went in, it should come out. The screen should be close in diameter to the pick up tube so maybe if you bent the tube enough to pull the screen straight up and out of the hole, it would come out??

[gnrphil]

Is it not possible to remove the ASV from the pick up tube without removing the tube from the tank?

[freezerfiller]

Aug 28, 2016 14:37:27 GMT -6 gnrphil said:

Is it not possible to remove the ASV from the pick up tube without removing the tube from the tank?

Yes, just unscrew it from the pickup tube. There is a stainless spring loaded ball bearing in there that keeps fuel from siphoning into the bilge. I'm not suggesting anyone remove theirs, but I threw mine as far into the gulf as it would fly. I haven't had it stick since...

If your fuel line goes below the top of the fuel tank anywhere in it's route to the engine, it could potentially leak there and siphon out several gallons. That is why they are required. On mine, it doesn't, but I guess in seas, it might could, and is probably more of a liability insurance policy by the manufacturer.

[deke]

OK, thanks for the picture and the advice. I did spend a little time trying to get the ASV out of the pickup tube, but it was tight and appears to be pressed on over the mushroomed nipple. Mine looks just like the picture, just add lots of corrosion. I'd spent some time trying to bend the tube and backing the ASV out of the tube. No joy made me realize I needed to get in here and ask you gents for help. Guys, I'm not as flexible as I used to be, and my neck and back told me I'd hit my limit for that round. But, if your saying I can clamp the tube with some vice-grips and just twist the ASV until it backs out, I'll try again. Not a easy locale for tools that need space to work, but getting enough leverage on that assembly to pull it out of the tank isn't a piece of cake either.