Primer bulb goes flat- Please help

Hello,

Recently I was out on the water going full speed (60 mph) then all of a sudden the speed back way down to about (5 mph) and then would eventually stall out. I checked my bulb and it was completely flat. Tried starting the engine and nothing. I kept working the bulb to try and get some gas into it, eventually I was able to get the bulb hard again. Engine would then start, I would get up to top speed again and then the same thing would happen. I checked the gas line going from the stationary gas tank to the bulb and there was a gash in it. Replaced the line and the motor ran fine for the 1st couple hrs the next time I was on the water. Then it happened again. Bulb goes completely limp and flat, very difficult to get it to medium hardness again. It would then run at idle speed but eventually stall out. Does anyone know why this might be happening? When I installed the new line I just cut the new gas line to the appropriate lenght and put a screw clamp on each end. Is there any kind of sealant I should have applied at the connections? Any help you can provide would be greatly appreciated.

Thanks,
B

Re: Primer bulb goes flat- Please help

Likely some kind of plug in the fuel system back of the bulb. Anti-siphon valve, fuel pickup screen, or tank vent are most likely. Good luck!

Pretty common problem. Do a search on this site and you'll get lots of answers!

Re: Primer bulb goes flat- Please help

fuel tank vent????????

Re: Primer bulb goes flat- Please help

What about the fuel tank vent? What should I look for and where is that located?

Re: Primer bulb goes flat- Please help

The fuel tank vent should be a thru hull fitting, below the rubrail, somewhere near the fuel tank. If the tank is in the rear, look on the transom, or side of the boat. Check it for clogs.

You can leave the tank filler cap loose and test the motor to see if that helps. If it does, it is very likely a fuel vent issue. If not, it is very likely what Marktwain said.

Re: Primer bulb goes flat- Please help

or it could be time for a $25.00 fuel pump rebuild kit

Re: Primer bulb goes flat- Please help

starcraft1982 said:

or it could be time for a $25.00 fuel pump rebuild kit

Click to expand...

The fuel pump is just fine. It is pulling a vacuum on the fuel line to the tank, and somewhere there is a restriction so that the vacuum goes high enough to collapse the primer bulb.

The fuel line is either OK, or it is collapsed inside. Pull it off the tank, stick it in a coffee can or oil bottle of fuel, and pump the primer. If it sucks fuel and the primer goes firm, it's all OK to there.

Now pay attention to the tank. One fellow on this site fought this problem for years, never believing there could be a problem with the vent. Finally he ripped it out and looked, and lo, some ace (usually spelled with a double s) stuffed a cigar butt into the vent line.

Another common occurance is the foil seal from an oil bottle gets into the gas tank, and gets sucked up against the fuel pickup strainer.

Check it out, it ain't rocket science. However, the fuel pump is obviously in very good shape.

hope it helps
John

Re: Primer bulb goes flat- Please help

Thanks John and everyone else who replied. This site is great and has a ton of good info because of people like you. I will try these suggestions tonight and let you know what I find.

Thanks again, I really appreciate it.

B

Re: Primer bulb goes flat- Please help

I agree with the vent or plugged pickup advice. I have a 12 gallon plastic tank with a screw type vent in the gas cap. Went about 15 miles before the motor started surging. I had forgotten to unscrew the vent to open it. The fuel pump worked so well that the tank was about 1/4 squashed.

Re: Primer bulb goes flat- Please help

You need to clean out your fuel tank, theres crud in it clogging up the screen that is inside your gas tank which filters crud out ! Had the same problem, It takes alot to clog or completely block a vent line from gas tank which should be present!!!

Re: Primer bulb goes flat- Please help

I have has mud dabber wasp plug my pee hole on the motor blocking the water. Possible for the fuel vent? Maybe the wasp like the smell of gas, lol

Re: Primer bulb goes flat- Please help

ifixf18s said:

I have has mud dabber wasp plug my pee hole on the motor blocking the water. Possible for the fuel vent? Maybe the wasp like the smell of gas, lol

Click to expand...

I freak when mud dabbers fly around my pee-hole. They are a type of wasp you know.

To the op, get in the flat bulb situation again and remove the gas cap. There is an obvious restriction up stream from the bulb. Process of elimination.

Geeze, may need a urologist!

Re: Primer bulb goes flat- Please help

Ok...so let me start off by saying I am far from being a mechanic and this is my first boat, so I am struggling trying to find the vent you guys are referring to. Let me give you a brief explanation of what I am working with. I have a 2000 Nitro NX882 bass boat with a 150 hp Merc. The gas can is built into the rear of the boat and I would say it holds about 15 to 20 gallons of fuel. I didn't have much time last night but did look around for any kind of vent and was unable to locate it. Where are possible places I should be looking for these plug up areas? How big and where exactly would the vent be? I put the ear muffs on last night and the motor fired right up as usual. The ball stayed hard, but my problem has been when I get it up to stop speed and then the ball goes limp and flat. Very difficult to get the bulb to re-inflate. If anyone has a picture of what I should be looking for that would be of great help. Thanks for taking the time.

B

Re: Primer bulb goes flat- Please help

For plugged vent, remove the gas cap (as others have said) and go out and run it. If you still have the problem, it's likely not the vent.

But...you can just google image search or search any boat catalog for a tank vent or gas tank vent and you'll see pics. Now, if you're feeling like a noob...I had to do exactly the same thing :redface: but as soon as I saw it I knew exactly where it was because I'd looked at it a million times (but didn't know what it "did").

Anti siphon valve is usually in the fitting that connects your gas line to your gas tank and is a pretty likely culprit, I'd say.

If it's a plugged screen, it'll take a little more work. I would expect you'll have to get inside the tank, I'd guess. Never had to go that far. Hope you don't either!