2004 CD25 fuel fumes in Cockpit

L

Lighthouse Express

New member
Since I purchased my 2004 CD25 I noticed the smell of fuel in the cockpit. Stronger with the canvas enclosure or warm weather. The fuel smell is emerging strongest from the rear starboard side below the splash well.
Am I glad I quit smoking when I was 24...

I did check the following:
*Fuel stains of any kind below cockpit deck where possible
*Razor filters for leaks
*Dual engines fuel lines for seepage or wet spots
*Fuel supply 90 degree brass connectors for leaks or cracks
*For blockages of the two vent lines
*For leaks around the gas level sensor unit

Since the 2004 model does not have a removable cockpit floor (darn thing) I only was able to take a look at the main filler hose and vent hose via mirror and flash light through the round access hole above the gas level sensor. Nothing obvious with the very limited view I had.

No obvious leak that I can find...

Perhaps there is a common problem with the 2004 CD25 fuel system I don't know of???

I got a brand new Magma BBQ grill I want to try out...
 
Check the vent hoses for cracks too. Mine were cracking after 10 years and you are right there in the ballpark.

Use your nose or another persons very carefully in a windless environment to see if you can pinpoint in area better as well. And no lighting that BBQ before you find the source. The tank on our 25 did have a leak in 2009 and needed replacement but that resulted in gas in the bilge and was much more obvious.
 
When we got Journey On, we would notice gas smell/vapors in the cockpit. After careful consideration and meticulous scientific consideration, I arrived at the following elegant solution:

Since there are 2 ea fuel vents, one on each side, with fairly large openings, I wrapped blue masking tape so as to block off the majority of the vent area. No more gas smell.

Now before the hoi polloi respond I'll point out the following. The vents accommodate fuel expansion and fuel usage. Both occur at a very slow rate. In addition, when one is fueling, the vapours exit through the open fuel cap. Therefore the excess vent area only leads to fume emission as the boat gently rocks.

Replace the blue tape every 3 years, needed or not.

Boris
 
Lighthouse Express--do you have aluminum or plastic tanks. I know of at least one plastic tank which leaked. On the other hand, if the boat has been operated in Salt water, under some circumstances, there has been corrosion of the aluminum tanks. Unfortunately C Dory did not prep and paint the tanks with coal tar epoxy, as they should be. I agree look at all of the hoses--from fill to vent, and fuel hose to the tank--probably time to change out at least the fuel and vent hoses. Check all of the hose clamps very carefully. Do you have dual fuel fill as Boris has, or just one fuel fill as my 2003 had (with plastic tank).
 
Thanks for all of your replies...

The fuel tank is a plastic one and it does have a fuel sender unit I have access to.

I will take your advise and go ahead with the replacement of the dual fuel hoses and the one of the vent hoses in addition to replacing the fuel sender gasket. Since the floor is permanently installed I cannot get to the other vent hose without cutting into the deck.

Thanks again,
Heinz
 
Would agree with Boris. My 06 has vents on port & star. upper area of each in general area of filler caps on sides. While on lift happened to get whiff and stuck my nose a little closer and very strong. If sitting in cockpit in a very gentle cross wind would get the smell too. Still a good idea to check hoses too.
 
I would check the fuel sender gasket visually then determine if needed replacing.
It may be fine and does not need replacing plus avoids the possiblity of stripping threads in the tank leading to more work and I dont know how it is installed on a palstic tank but familar with WEMA sender unit on metal tanks
 
If you are replacing a gasket in a plastic tank--rather than tighten it down, use something like the Permatex Form a Gasket 2, coating both sides of the gasket--you can use the old gasket as a pattern, make a thin gasket, and then install with the Permatex. Should be good for a long time, since the F A G 2 remains soft for many years. (wear gloves--it is the dickens to get off your hands).
 
My 2008 25CD has a similar gas smell in the cockpit only when the wind blows a certain direction as Boris and Free Money have pointed out. For a while I searched around, but have since given up since I can smell it coming from one of the two vents under certain conditions.
 
It's quite well discussed in other forums such as the Hull Truth that some plastic tanks will allow some out gassing of smell. Do check all connections and all over but if nothing is amiss it may be your tanks are emitting a smell only
Moeller's web site (tank mfg) addresses this. A slight smell may be noticeable but it isn't combustable vapour.
George
 
I just had a similar experience as Heinz with my 2004 CD25. However I believe Scooter is one of the first 25's to be built with the removable cockpit floor. So I removed the fill/vent hose covers and cockpit floor to inspect for leaks and found nothing. Curiously there is a second hose clamp on the hose from the tank to the Racor (closer to tank fitting) that is just floating loose. It doesn't appear that the tank fitting barb is long enough to support 2 clamps?

Unless the aluminum tank has a pinhole leak (I hope not) I am going to go with Boris's conclusion and tape up my vent fittings to reduce the vapors.

However I have a related question for those of you who have removed/replaced the cockpit floor. What sealant was used by the factory for this? It appears to be pretty robust and I would like to replace it with the original stuff or another recommendation from the collective wisdom of the Brats!

Thanks in advance,

Dave
 
Scooter3":12kwu957 said:
Curiously there is a second hose clamp on the hose from the tank to the Racor (closer to tank fitting) that is just floating loose. It doesn't appear that the tank fitting barb is long enough to support 2 clamps?
Click to expand...

It's pretty common for barbed fittings to only really have room for one clamp to fit properly. In this case two clamps can be detrimental because one lies partially on and partially off the fitting, and that can damage the hose. I oftentimes here that "two clamps are required below the waterline," but this isn't true that I know of. ABYC guidelines (which I find to be very good), only call for two hose clamps in in two locations:

1) Fuel fills (fuel fills normally have very long barbed sections, so this works well)
2) Exhaust systems (inboard engines)

Not that two isn't good or can't be used in other places, but I prefer to use one good clamp and call it a day -- rather than two where two won't be well supported by the fitting (I use AWAB clamps).

I have seen people put a "spare" clamp on the hose to slide into place when the first one gives up the ghost (many hose clamps, even if "stainless," have mild steel parts so don't last as long as the hose). Again that's a place where I would rather just use one good clamp that I have confidence in.

On the odor: Have your fuel hoses permeated? i.e. is fuel odor coming through them and that is what you are smellling? If so, perhaps consider changing the hoses for new hose (good, fuel rated hose, such as that made by Trident or similar). I put all new fuel hoses/clamps on my boat/engine when I got it just for piece of mind, especially with "modern" fuels (which I try to avoid in favor of non-ethanol gas).

On the cockpit sealant: I can't see the joint, but if it is held down by mechanical fasteners, and thus the caulk really is just a sealant (and not holding the thing down), then I would want to use something relatively easily removable/replaceable, since the cockpit deck may have to come off again. I like butyl for that sort of thing (it does a good job and is very easy to clean off when needed). It may make a small grey line around the edge though. Of the "other" (more adhesive) caulks, I'd probably go with 3M4000, since it should stay white (polyurethane, such as 4200/5200, can yellow in UV light). Or, if the joint is suited for it, perhaps a gasket instead of caulk (likely this is not the case).

Will be interesting to see what the 25 folks say, since they have likely seen the joint and I haven't.
 
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