Exhaust Fumes in Engine Compartment

[burtonman]

I have a 2008 Searay 185 boat with a 4.3L engine. I recently winterized the boat by changing the oil and filling up the tanks with gas and additive etc. I then covered the boat with a tarp completely to protect my baby from the elements. A few weeks later I needed to get something from the engine compartment and the gas fumes were pretty bad. This is the first time I have had the boat closed up for an extented amount of time. Is this normal? No leaks apparent.

 

[Earl's 86 Swirl]

If the fumes are strong, and there are no apparent leaks my next guess is the fuel tank. Did you fill the tanks absolutely full? If so, the tank could be venting the excessive pressure(and fumes) into the engine compartment. Just a thought. I'm not a boat tech, but know bit about autos.....

 

[burtonman]

I did fill the tanks til the pump cut off automatically. I've been told that filling up the tanks helps prevent excessive moisture build up in the tanks by not having as much air in the tanks. Should I pull out some of the fuel?

 

[Earl's 86 Swirl]

The advice to fill them up to prevent moisture build up seems reasonable, but that's my best advice. It's not going to hurt anything to drain some off, let the engine compartment air out and see what happens. (something easy to do while waiting for more posts!) Good Luck!

 

[Chris]

Well one thing worth mentioning, that you might, or probably already know is that a fuel leak in a I/O is a very serious safety hazard.

Therefore, if you do ihave a leak, make sure it gets corrected before you start up your boat or even putz around with anything that creates a spark like your battery as one example.

One thing that came to mind....

Have you checked to see where the vent for the tank is located?. Perhaps your cover is covering up the tank's vent and then because you filled the tank right up, perhaps the fumes are gathering or being trapped inside of the boat?

I'm not sure if that's the case, but I thought I'd throw that idea out there.

-Chris

 

[dave]

chris is right, gas fumes will settle to the lowest part of the boat, namely the bildge so make sure your vent is uncovered.

 

[RNC]

I agree with Chris also. I have also noticed in smaller boats when the tank is full and because a boat runs a open fuel vent unlike a car. The movement of you getting in and out of the boat tends to purge the fumes out of the tank.

I have also seen the fuel filler hose get hard and loose its seal on the tank.

 

[bigredinohio]

Something to ponder would be a blower fan to help vent the fumes from the compartment to prevent explosion while starting however the source of the fumes should still be found.

 

[RNC]

Something to ponder would be a blower fan to help vent the fumes from the compartment to prevent explosion while starting however the source of the fumes should still be found.

That has been a mandatory feature on any I/O since the seventies.