Gas Smell after Running Engine

This forum is for comments and the exchange of information relating to Trojan Boats and boating. Please do not post used parts or boats For Sale in this area. For general, non-boating topics please use our "General Discussions" section.

Note: Negative or inflammatory postings will not be tolerated.

Moderators: BeaconMarineBob, Moderator, BeaconMarineDon

Post Reply
bigralph
Registered user
Posts: 54
Joined: Sun Feb 24, 2013 8:54 pm
Location: Memphis, TN

Gas Smell after Running Engine

Post by bigralph »

Good Morning:

1990 F32 Twin Crusaider 350; 850+ hours on tach; both engines rebuilt to some extent by PO - no knowledge of who, what, where.

Every time I run the engines, there is a strong gas odor in the boat afterwards, sometimes a sheen in the bilge. Yesterday, I replaced the fuel filter on the port engine after previously replacing the stbd fuel filter. The reason replaced, stbd engine died last time; suspected water in fuel from sitting in harbor; took stbd fuel filter off, discovered one of 3 oem gaskets/o-rings installed. After replacing fuel filter and installing all 3 o-rings, stbd engine had greater power and sounded better. Decided to check port engine and only one gasket installed. (Racor S3232TUL) I hoped that replacing the fuel filter and seating properly might eliminate fuel smell after ignition. No dice. Carbs were rebuilt immediately prior to purchase. They look nice, but can't tell you I know enough to know if there could be a problem with rebuild. Both bowls on bottom of fuel filter cartridges are new and replaced at same time. The STBD fuel filter manifold (don't know what that should be called, it's the t where gas comes in and is routed through filter then goes to engine) showed some blisteringon STBD side when the filter was replaced. I don't see any evidence of leakage at the fuel manifold that switches between 2 port and 2 aft tanks. I don't see any obvious leakage on hoses and now that I"ve ventilated overnight, i don't smell gas. Typically, the only time I smell gas is a couple minutes after turning the engines off.

Oh yeah, I'm a live aboard and it sucks to come home to the smell of gas.
ramblin
Registered user
Posts: 31
Joined: Sun Dec 12, 2010 10:40 am
Location: Buffalo, NY (lake erie)

Re: Gas Smell after Running Engine

Post by ramblin »

I had a similar problem that i only smelled gas after shutdown and couldn't find the leak. Turns out it was the fuel/water seperator, the thing that looks like a spin on oil filter. The was a pin hole up high and when running didn't leak but when i shut off the engine it would leak until the gas dropped below the pin hole. Hope that helps
User avatar
75 Tri Cabin
Registered user
Posts: 39
Joined: Sun May 06, 2012 8:33 pm
Location: Anderson,SC
Contact:

Re: Gas Smell after Running Engine

Post by 75 Tri Cabin »

Look down the throat of the carb after you shut the engines off. You might see gas dripping it it. Sometimes the needle and seat might have a piece of trash it it. This will make the carb flood and until the gas has dripped out of the carb, you will smell gas. Also check your vent hoses, they may be cracked. When the fuel is swishing around in the tank it creates a build up of fumes and will seep thru the vent hose inside. Had both these problems before. Both these problems will finally stop the gas smell after it sits awhile.
Jack
______________________________________
Day on the water is better than a day at work.
1975 36' Tri Cabin
1967 18' Aristocraft hardtop
Hartwell Marina, Hartwell GA.
rickalan35
Moderate User
Posts: 790
Joined: Mon Feb 06, 2006 1:37 pm
Location: smiths falls, ontario, canada

Re: Gas Smell after Running Engine

Post by rickalan35 »

Hi - Unfortunately, I had the same symptoms a few years back and it turned out to be pin holes in my starboard gas tank. Very big problem. I had to remove both tanks and have them replaced.

There is an access hatch, believe it or not, in the steps leading down to the rear stateroom. The top step's riser is on a hinge that makes the riser fold outwards, for a peek at the rear end and bottom surface of the starboard gas tank. You can test that area for gas seepage.

I removed both tanks and replaced.

Rick
Trojan 1994 370 Express, 502 Bluewaters
Post Reply