Fuel evaporates and engine leaking fuel

[lmuss53]

Be careful looking for issues you don't have. I think the enrichener is the source of your hard starts.

Unless you have had some performance problems beyond the hard starts don't mess with linkage that is otherwise working. Maybe post us up a picture of what you think is wrong with the linkage.

80 pounds of compression on the 4 stroke is fine.

Pull the hose off the discharge side of the enrichener and see if it gives a squirt when you click it. Don't be afraid to click it 6 or 8 times,

Everything under that hood is there with a purpose, please be careful about tightening, un tightening, adjusting, moving, bending, you get it, anything under that hood. You can create issues that are mind boggling to try to un create. They can also get very expensive if you have to take it in for repair.

 

[Marinescout]

I didn't mess with the linkages just seen where the plastic bushing was cracked and seen the rod popping in and out. I did a pressure check a spark test and then looked at the butterflies in carbs which is why I seen the linkage issue. I'll try that on the silenoid. That's a good idea. Thanks

 

[MH Hawker]

how is finding the leak going

 

[Marinescout]

I believe it was like a poster said the vent seemed to not be working so I believe the fuel was pushed out through the line and coming out the carbs. I'm still checking on the silenoid and will post on that soon.

 

[lmuss53]

A little positive pressure will speed it up, but if your tank is above the carb (most pontoon tanks are), you need only gravity and an open path to let the tank drain through the carb or a cracked hose. that's why I think you need the shut off or a disconnect of some sort.

 

[ahicks]

I think the valve might be handy while troubleshooting the leak, but my preference for the long term, would be to find and repair that leak.

 

[lmuss53]

I agree completely ahicks, the shut off is a just in case.

I tend to pop the line off of my tank at the end of the day, because I have come back to an empty tank on the pontoons on one or two occasions over the years.

 

[Marinescout]

Ordered the fuel cutoff fromamazon its from Atwood so I believe it will be marine use. Also order a new fuel line a fuel filter for inside the motor a fuel filter for the water separator and a 1-1/2 inch marine grade hose and filler neck with cap so I can run my fill outside so I don't have to raise the rear sun deck for fuel. I'm also going to drill a hole and put a vent tube in. I also order a new pickup tube and gas gauge float but I am keeping the bulb it is a mercury and it was over 30.00 six months ago so I feel it is ok. I seen some boats with the line hanging on the back rail before it goes into the bulb and on to the engine is this just for ease of access to the bulb or does it help on feeding fuel to the engine?

 

[ahicks]

Easy access to the bulb would be my guess.

 

[Silver Eagle]

Can't you just put in a **** valve on your fuel line near the motor.?

 

[Marinescout]

That's what I order was a **** valve 3/8 inch through and through and I think it will work fine. The one on my lawnmower hasn't stop yet and it's been in the weather for ten years

 

[Silvertip]

Built-in tanks usually have an anti-siphon valve. That's the fitting to which the fuel line connects at the tank. It has a spring loaded check ball in it that is supposed to prevent fuel from siphoning out of the tank. The tank on a pontoon sits higher than the engine so any leak along the fuel system could result in fuel loss if the anti-siphon valve is malfunctioning or if someone thought it was unnecessary and replaced it with a standard barb fitting. Fuel pump drawing fuel from the tank unseats the check ball during operation.

 

[Marinescout]

Mine was connected via a barb direct fitted. It is my belief after all the post on here and apparently my vent on the cap not working that my gas was pushed through the line and out the carbs. Thank you for the help in me figuring out where my fuel was going.

 

[Marinescout]

I also found a fill cap with lid that has a built in air vent so I can permanently attach it to the boat for easier fill ups and do away with the factory cap. That way I won't have to drill a hole and put a vent in my tank.

 

[Silvertip]

That enrichener does not PUMP fuel. It opens a port that allows pressure in the fuel line (from squeezing the primer bulb) to force fuel into the engine. If there is no pressure in the fuel line there will be no fuel movement in the enrichener system. You apparently are not using the fast idle lever on cold starts either. To repeat again, with the engine tilted, the floats in the carbs are not able to close the inlet needle and fuel spills out. Repeated rebuilding does not solve this. Water (and gasoline) flows downhill so unless there is an anti-siphon valve or manual shutoff in the fuel line, fuel will drain from the tanks. That's just the way physics works.

 

[Marinescout]

I always use the fast idle lever when starting cold. I also tried cranking it and pressing in on the key but nothing happens a except a click sound from the silenoid. But no fuel released. I can press the black button on top which I assume is a manual override down and see fuel being released and it fires right up. All this is after the primer bulb is as tight as it will go. So my conclusion after testing the silenoid and seeing that it is getting 12 volts and taking off the fuel line to the carbs and getting no fuel except when pressing the black button manually that my silenoid is bad. Rather it pumps or not is irregardless it is suppose to (allow) fuel to the carbs when the choke switch on the key is pressed and mine apparently is not.

 

[Marinescout]

And from tilting the engine up with fuel in the carb bowl it ran out until the carb was empty then stopped. It only seems to drain the little amount of fuel that is left then no matter how hard I pump the bulb it no longer leaks. I believe I posted that in an earlier post.

 

[Marinescout]

I'm installing a permanent hose fill and cap and doing away with the screw on cap. Does anyone know if the vent on the cap is enough to properly vent the tank or will I need to install an additional vent and should I run the vent hose from the gas cap back to the tank and add an additional line? My tank now only uses the screw vent on top of the cap.

 

[lmuss53]

I would vent the tank if are putting a filler neck on it more that just a few inches long. If not you may find that the fuel and air have a hard time getting past each other when you are filling the tank. If you don't use a long hose on the filler the vent in the pop top type fillers is sufficient.

I have an 11 gallon tank under the rear deck on my Sea Nymph. I have about a 3 inch hose between the deck and the top of the tank, where the fill hose is attached. I have no ventilation on the tank, only the built in vent on the pop top filler. I ran a 3/8 hose from the filler vent barb to an outside vent under the outside rubrail. I have never had any problems with filling the tank, or having anything splash, flow or otherwise come back up or out the vent hose.

If the tank will fill with the new setup and the vent is weatherproof the vent in the new filler cap should be sufficient. It will only need a hose if you are worried about overflow or need to protect the barb from the weather. You don't want to give rain or splash a path in to your tank.

Obviously the tank on the V hull is below the engine so I don't have any of the issues of bleeding off of the fuel that you seem to have experienced. No matter how your fuel leaked off before chances are it could again, a spring loaded check valve, manual disconnect, or a shut off, as close to the tank as possible is the best insurance against this happening again.

If your enrichener does not pump, try unhooking that same output line from the enrichener and putting it in a container. With the kill lanyard unplugged so the engine won't start, try cranking the engine over, while activating the enrichener, and see if the fuel pump pushes any fuel out the enrichener hose.

 

[Marinescout]

Didn't think about it coming in just going out. Great advice I'll try that and let you guys know. And thanks for the tank advice I really dont won't to drill a hole in my tank to put a vent line which is why I want to go with the full cap that had the barb on it for a vent. Thank you.