mercruiser V8 5L fuel leak

[dlogvine]

Boat is Ebbtide Champione 210 with v8, 5.0 mercriuser engine.
I noticed a strong fuel smell in the engine compartment after I run the boat even a little. It shows only after engine start. However I was not able to find a source of this leak. It definitely does not occur from the carburetor, since the engine does not show any traces of fuel. I looked at the fuel pump and the water/fuel separator, but it does not look like there is any. Some traces of fuel appear in the bottom of the engine compartment under the engine. I wonder if the source of the leak is in a fuel hose from the fuel tank to the pump or maybe the fuel tank hose connector and fuel gauge lever. The reason Im asking for an advice instead of simply checking the spots is the difficulty in accessing these locations. The fuel tank is completely sitting under the floor and an access hatch for the fuel tank outlet is sitting almost perfectly under the wall separating the bench seat from the engine compartment. Any advice is greatly appreciated.

 

[Scott Danforth]

check to see if the clear hose from the fuel line to the spark arrestor or carb has any fuel in it. if so, your fuel pump has failed.

 

[dlogvine]

The boat runs fine, I just came from the lake trip where the engine ran for more than an hour. The fuel pump is working without a doubt. Im a little confused as to how a failed fuel pump can cause a fuel leak into the engine compartment?

 

[Rick Stephens]

On an automobile pump, if the diaphragm in the fuel pump has a split or crack in it, it will leak fuel either on the ground or into the engine block while usually still running. On boat either destination can cause an explosion. So a marine mechanical fuel pump has a clear line from under the diaphragm to the top of carburetor. Goal being to dump leaky fuel into the cylinders instead of into the bilge. Scott's question related to whether that clear tube had any fuel in it and was attached securely.

I think your '98 has an electric pump though, so that clear tube would not be installed. If you have a fuel smell you have a leak. Most likely somewhere between pump and carb. Dangerous.

 

[Bt Doctur]

Can also be the tank. Start at the motor . its fuel system and work toward the tank

 

[Bt Doctur]

I noticed a strong fuel smell in the engine compartment after I run the boat even a little. It shows only after engine start. However I was not able to find a source of this leak. It definitely does not occur from the carburetor, since the engine does not show any traces of fuel. I looked at the fuel pump and the water/fuel separator, but it does not look like there is any. Some traces of fuel appear in the bottom of the engine compartment under the engine

The boat runs fine, I just came from the lake trip where the engine ran for more than an hour. The fuel pump is working without a doubt

Did you know that 2 oz of liquid gasoline turned into vapor will turn your boat into little bits of fiberglass in a hurry/ Go play the Lottery

 

[dlogvine]

Did you know that 2 oz of liquid gasoline turned into vapor will turn your boat into little bits of fiberglass in a hurry/ Go play the Lottery

I am not sure what was this comment about? Does it look to you like I love to play with matches and set my boat on fire or turn it into a floating bonfire? Im asking this question because I am concerned about the boat safety. I noticed the gas presence in the water when I opened the drain plug and drained the water. I smelled the gas before but did not see any leaks and thought it was related to the engine running. I will definitely look into the source of the leak, and that is the reason for my question. If I wont be able to find it myself I'll take it to mechanic.

 

[Bt Doctur]

I am not sure what was this comment about? Does it look to you like I love to play with matches and set my boat on fire or turn it into a floating bonfire? Im asking this question because I am concerned about the boat safety.

Operating a boat with a known gas leak and smelling gas odor is like pulling the pin on a grenade and holding it to see when it will explode.
If you have the mechanical fuel pump, check the tell-tale hose for liquid .If electric fuel pump ,disregard that.
If you see no wetness on the hoses, filters or fittings with the engine running then you must suspect the fuel tank, fuel vent , fuel fill or the gauge sending unit for leaks. The tank compartment should have a drain into the bilge.Open any access ports to visually check hoses and clamps
If the bilge is completely dry park on a very steep hill facing down for 5 minutes then facing up for 5 minutes.
A leak at the tank will show fuel in the bilge

 

[Scott Danforth]

my 2002 5.0 had a mechanical fuel pump on it with the clear line up to the carb. your 1998 may have it as well. you need to check

 

[dlogvine]

Thank you guys, will do so immediately, will take it to the mechanic if wont identify the leak source myself.
The fuel pump is mechanical and will check the clear tell-tale line first, also I did not see any gas leak on the engine. Looks to me like the leak was either from the hose connecting the tank to the fuel pump or the fuel fill. The reason I did not check these places is that they are hard to reach, would have to take the bench seat apart to reach the access port.

 

[dlogvine]

I cleared up under bench storage and opened the fuel tank hatch. One of the screws used to tighten up the fuel gauge sender was way too long and was not tight so the fuel was leaking through the little opening there. Fixed now, will test the boat tomorrow

 

[harleyman1975]

Let's hope you found your Huckleberry!

 

[dlogvine]

another little problem, when I tightened the screws, I found that electronic part of the sending unit was barely holding there, it was almost broken. It is Moeller brand and I'm trying to find a replacement for just this part. Should I keep looking for it or just completely replace the fuel sending unit?