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View Full Version : Help me find source of gas fumes in 99 22C...



Jamesbon
01-22-2008, 06:12 PM
Hi guys,
Everytime I uncover the 99 22C, I smell gas. Not enough to ignite, but no mistake, it's smelly and I'm not comfortable with it.

I have a 99 22 Classic with 7.4L Mag MPI 385 HP. She also sits covered under a custom shrink wrap full cover that probably doesn't breath much, as it's made of "plastic."

Over the holidays I cut a hole in the cover to expose the tank vent on the side of the hull, thinking this would alleviate the problem. Well, tonight I uncovered her and the same smells are present. Aside from the obvious, it worries me a bit as I continuously run a "dehumidifier" in the boat.

I've poked around under the deck from the forward void with a flashlight. The fuel fill and vent hoses appear to be free of cracks of loose connections. The engine appears to be free of leaks as well. One place I'm concerned about is where the fuel inlet hose passes from the rear bulkhead to the engine. The diamond plate firewall seems to bind the hose a bit. Will look into that a little more tonight.

Are there any areas you can think of I should check?

DonziJon
01-22-2008, 06:42 PM
Uncovering the tank vent would have been my FIRST reaction. Covered boats seem to harbor musty scents when you climb in during the winter. Fuel will expand and contract with big temp changes. May be nothing to get concerned about. Keep a Nose on it though. John

Morgan's Cloud
01-23-2008, 09:50 AM
Ahh , bless a functioning nose eh ?

You have every right to be concerned and want to track it down , by any chance do you have a plastic fuel tank instead of alum ?

MOP
01-23-2008, 10:20 AM
Nate the fuel sender many times will appear dry and not leaking until you fill the take. Once filled tilt the boat you may see it weep, also a good idea to press on the tank top it will flex a little that may make it leak. Sender leaks for the most part dry quickly when the boat is at rest.

Phil

VetteLT193
01-23-2008, 10:28 AM
Are you sure it's gas fumes, or is it boat smell? Every boat I've ever covered has a unique smell to it, sorta gas like but not really. it's like a combination of bilge funk mixed with vinyl, canvas, and engine smells.

BUIZILLA
01-23-2008, 11:01 AM
fuel sender base gasket

catch 22
01-23-2008, 04:52 PM
Uncovering the tank vent would have been my FIRST reaction. Covered boats seem to harbor musty scents when you climb in during the winter. Fuel will expand and contract with big temp changes. May be nothing to get concerned about. Keep a Nose on it though. John
Mine does the same thing.I was told that the fuel expands and contracts when it's hot. And having it cover up makes it worse. When you uncover it does the smell go away? Mine does. I think if you had a fuel leak you would smell it all the time.

Barry Eller
01-23-2008, 05:39 PM
Mine does the same thing.I was told that the fuel expands and contracts when it's hot. And having it cover up makes it worse. When you uncover it does the smell go away? Mine does. I think if you had a fuel leak you would smell it all the time.


Same here. I attribute some of the odor to my carb.

I know I have no leaks. Aluminum fuel tank is in great shape. New gas lines, fuel sender and gasket less than a year old.

Could some of the fumes be coming from the air filter/intake on injected engines?

justleft
01-23-2008, 05:40 PM
Are you sure it's gas fumes, or is it boat smell? Every boat I've ever covered has a unique smell to it, sorta gas like but not really. it's like a combination of bilge funk mixed with vinyl, canvas, and engine smells.

Oh yea, even my c0ckpit cover smells like that ! (need little guy holding nose)

New cover on my birthday list.

Air 22
01-23-2008, 06:09 PM
Is your bildge clean? If not try wiping down with a good degrease spray...old oil/gas residue will smell. We have a 1995 22 with a 502 CARB no fuel/oil smells and she has custom fit cover and tarp over that ...keep us posted on your results...:smash:

MOP
01-23-2008, 06:52 PM
Rule out carb stink! Fuelies don't smell!

Dr. Dan
01-23-2008, 09:36 PM
Nate mine does exactly the same thing...it does dissipate after its uncovered, it very well could be what Buizilla said... its definitely not a leak...but mine is stored for so long it has actually changed the color of my inside lining of my mooring cover...

There appears to be a bacteria or mold that likes Petro, It is only where the vents or any direct venting occur...and you see this pattern of like a fume related mold or mildew...

It has baffled me for years, I have been all through mine, and a slight leak or seeping like MOP & Buizilla describe fit the bill.

How complicated is that to replace? Is it right under the access hatch? Either way it sounds like potentially no fun.

As a result... I never smoke a Cigar or allow anyone to smoke on the boat...not that I would anyway...but still just the same.

Hmmmm

Doc of Gaseous & Semi Unidentified Methane Based Sub Human Compulsive Fuel Disorders & Stuff Like That There :toilet:

Barry Eller
01-23-2008, 11:02 PM
Nate mine does exactly the same .
Hmmmm
Doc of Gaseous & Semi Unidentified Methane Based Sub Human Compulsive Fuel Disorders & Stuff Like That There :toilet:
Doc, I prescribe "BEANO" for your condition!:jestera:

RedDog
01-24-2008, 06:51 AM
my '98 MPI does the same thing. I don't think it is a leak

Jamesbon
01-24-2008, 08:07 AM
Wow! That's GREAT info. fellas. It's nice to know I'm not alone.

Responses to all;

It is a poly tank.

I disconnected the vent hose and blew into it till I was about to passout, then capped off with my thumb, I couldn't hear or smell any leaks....until I uncapped the hose....whew.

I will take a closer look at the sender and gasket.

It's definetly gassy smelling as opposed to "that boat smell."

Yes, once uncovered, the smell goes away and does not come back. I always check the bilge and low lying voids in the hull, but she never smells of gas when I'm using her. No visible puddles or anything. I even stuck an old curtain rod down through all of the c0ckpit drains and swirled around on the bottom of the hull, but still no signs of gas.

Yeah, the bilge is clean.

Yes, the fuel sender is located under an access hatch. Shouldn't be too hard to r&r.

Air 22
01-24-2008, 08:17 AM
Wow! That's GREAT info. fellas. It's nice to know I'm not alone.
Responses to all;
It is a poly tank.
I disconnected the vent hose and blew into it till I was about to passout, then capped off with my thumb, I couldn't hear or smell any leaks....until I uncapped the hose....whew.
I will take a closer look at the sender and gasket.
It's definetly gassy smelling as opposed to "that boat smell."
Yes, once uncovered, the smell goes away and does not come back. I always check the bilge and low lying voids in the hull, but she never smells of gas when I'm using her. No visible puddles or anything. I even stuck an old curtain rod down through all of the c0ckpit drains and swirled around on the bottom of the hull, but still no signs of gas.
Yeah, the bilge is clean.
Yes, the fuel sender is located under an access hatch. Shouldn't be too hard to r&r.

FYI...not sure but you might wanna ck that tank very closely as ethonal is a real problem for fiberglass tanks? see below..
Ethanol suspect in older fiberglass gas tanks
Boat/US Magazine, Jan, 2006
Older fiberglass gas tanks may fail or cause engine damage when filled with gasoline formulated with ethanol, according to damage reports collected by BoatU.S.


BoatU.S. has learned of more than 30 cases of fiberglass gas tanks manufactured before the mid-1980s that produced an engine killing sludge or began leaking after being filled with 10% ethanol gasoline.

The investigation is ongoing, but it appears that 10% ethanol gasoline, which was introduced in the Long Island area to replace gas additive MTBE in late 2004, may be attacking the resins used in older fiberglass gas tanks. These tanks were standard equipment on some Hatteras and Bertram models and may be present on other boats of the same era. Diesel tanks are not affected.

Related Results
Storing...
Running ethanol.
The engine damage appears to be due to a tar-like substance--possibly from the chemical reaction between the resin and ethanol--causing hard black deposits that damage intake valves and pushrods, ultimately destroying the engine. Early symptoms may include engine backfiring and hard or sluggish starting in which the engine turns over slowly. Affected engines may not reach their rated rpm.

Fuel filters have not captured the substance. The only way to know for certain is to pull the carburetor and inspect the underside for a black, gummy film.

BoatU.S. has also confirmed reports of tank wall failure in some of these tanks in which gasoline was found leaking into the bilge. At press time BoatU.S. was awaiting the results of laboratory experiments to determine the exact cause of the problem.

New York and Connecticut boat owners have reported the majority of problems, along with one owner in California. Ethanol and MTBE are used to oxygenate gas to reduce harmful emissions. MTBE has been banned in half the states.

Anyone who has experienced these problems should send details to BoatU.S. at cfort@boatus.com.

COPYRIGHT 2006 Boat Owners Association
COPYRIGHT 2006 Gale Group

MOP
01-24-2008, 09:55 AM
Unless changed none of our boats have glass tanks.

mjw930
03-09-2008, 08:27 PM
Sorry to resurrect an older thread but I'm pretty sure the smell you have is coming from your fuel vent.

My new cover goes down over the vent and when I pull the draw string it pulls the cover tight to the side of the boat. The old cover did not cover the vent. There was no fuel smell with the old cover, there is fuel smell immediately after removing the new cover but it clears quickly.