Petrol smell????

jak2108

Seaman Apprentice
Joined
Oct 3, 2009
Messages
30
We have a mercruiser 4.3L and there seems to be a strong smell of fuel when idling. All fuel lines have been checked for leaks and are OK. The plugs have been checked and have no signs of fouling due to richness. Any ideas or is this normal
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,073
Re: Petrol smell????

No not normal.More info please??Carb or EFI,profile filled out.
Check the oil see if it has gas in it.J
 

180shabah

Rear Admiral
Joined
Mar 26, 2005
Messages
4,995
Re: Petrol smell????

definitely not normal, you need to find the source before bad things happen.
 

Fishermark

Vice Admiral
Joined
Oct 19, 2003
Messages
5,617
Re: Petrol smell????

As Jerry mentions - check the oil for gas. If you have a mechanical pump, the diaphram can rupture and put gas in the oil. Otherwise.... double and triple check all the fittings - including the fill and vent lines.
 

Flyin1500

Petty Officer 3rd Class
Joined
May 31, 2007
Messages
83
Re: Petrol smell????

As Jerry mentions - check the oil for gas. If you have a mechanical pump, the diaphram can rupture and put gas in the oil. Otherwise.... double and triple check all the fittings - including the fill and vent lines.

If you do get gas in the oil, is the only way to tell by smell, or will the oil look different?
 

Gary H NC

Fleet Admiral
Joined
Dec 1, 2005
Messages
8,972
Re: Petrol smell????

Depends on how much gas may be in the oil. Smell is the first check.
If it smells like fuel check the stick to see if the level is over full.

Also there should be a small plastic hose from the pump to the carb,(usually clear or yellow plastic)Check it to see if it has traces of fuel in it.
If so the fuel pump is bad.
 

Fishermark

Vice Admiral
Joined
Oct 19, 2003
Messages
5,617
Re: Petrol smell????

Also there should be a small plastic hose from the pump to the carb,(usually clear or yellow plastic)Check it to see if it has traces of fuel in it.
If so the fuel pump is bad.

That's true, but I believe they can also rupture internally and not leak out from the tube to the carb.
 

cr2k

Captain
Joined
Mar 19, 2009
Messages
3,730
Re: Petrol smell????

That hose is the vent so if it does rupture it will show in the tube.

We had a boat last year that wife keep saying she was smelling gas.
Turned out she was sitting by the tank vent fitting on the hull. If you are idling and maybe wind at the stern, this could be your problem.
 
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