DF-140A dripping gas from around the oil drain plug.

[ShellKnobCat]

I'm starting a new topic for this. I have posted about this gas leak before but I was unable to find where it was coming from. Today I found it. Gas is dripping from the opening around the oil drain plug - it never occurred to me to look there as I thought it was coming from the exhaust under the water. It drips about one drip every 2 seconds or so at idle but appears to slow down and stop at higher RPM around 2000 or so in neutral. I don't want to rev any higher in neutral and in gear and moving the water rises enough that I can't tell if it's leaking. The engine runs great, the oil level is not rising nor is there any gas smell in the oil. There is no leak anywhere I can find around the engine itself with the cover off. So I'm guessing that there is a leak somewhere lower or maybe where the fuel hose enters the cowling? I'm hoping to get the boat off the lift and over to the house this coming weekend, take the side cover off and run it on the muffs to see what I can find. Any thought as what I should look for would be greatly appreciated.

[Murray]

At the top of your VST there is a vent to vent fumes, these fumes are suppose to vent into your crankcase. If your VST float is set too high more gas than the engine requires will be allowed into the VST, that extra fuel will be pushed out the vent and into the crankcase(making oil). What if your vent line is disconnected at the crankcase and that excess fuel is dribbling down and exiting at your drain plug? I have no idea where this vent line attaches to the crankcase. Just a theory, no idea if my guess is correct.

[ShellKnobCat]

I agree it's something leaking that bis dripping out of the area around the drain plug. I'm hoping it's not the VST because that would be pretty complicated to fix. Hopefully it's a fuel supply hose leaking or something simple like that.

[ShellKnobCat]

Got the boat out today and the lower side cover off. It did not leak gas when I( took it out - the intermittent nature of this is weird. I did not have a chance to run it yet on the muffs but there is a hose that comes out of the top of the VST, down the left side and across through a hole on the forward side of the leg and is open. See attached photo. With where that hose drains above the hole for the oil drain plug is I'm pretty sure the leak is coming from that hose. I'll run it on the muffs tomorrow and see what happens. Is that the vapor drain hose from the VST? If so the fact that gas is coming from it does not seem like a good thing! Again this is a 2019 DF-140A with 627 hours on it and ir runs great.

[Murray]

Not sure if the hose you refer to is the VST vent hose. If you traced the vent hose to the hose you refer to then I’d guess you’re on the right track.

[ShellKnobCat]

Yes that is the evaporator hose. Comes out of the left side of the top of the VST then down to where is is in my photo. When I ran it on the muffs this morning almost steady stream of fuel was running out of it. I talked to my mechanic who is very good and trustworthy and he thinks it's a stuck float in the VST. I'm going to have him look at because it's something I don't want to tackle. Luckily he can get to it early next week. Hopefully won't be too expensive. I'll report here on what happens.

[Murray]

I’m surprised the hose is just hanging there, thought it was supposed to be venting into the crankcase.