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alka2710

Gas back splash while fueling

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Friend has a 2016 250 Suncoast and no matter how we fuel her up at the station or with gas cans and a shake and siphon we get a major gas back splash.  Always thought this was a venting problem.  Any tips or suggestions.

Al

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Although our boats are different, perhaps this will help [or not]. The vent design on mine would allow gas from the tank to slosh into the vent line, which was really long. So when I'd fill the tank, it would take forever because the vent line was clogged with gas. The back pressure from filling the tank would constantly click the pump off. Eventually the pressure in the tank from filling would push the gas in the vent line overboard. Quit a bit.

I had the vent line modified and the huge loop removed and a tiny one installed. Problem solved. BUT, I learned very quickly with the modification that when the pump clicks off, its full! If I don't its a big purge of gas out the vent.

Are you trying to add gas to the tank after the first click? Or is it spilling before its full? 

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My only experience with this issue was several years ago, and I found that the fuel filler neck had been installed upside down (an 06 Chap Sig 276),  The vent tube was therefiore below the filler tube and so when filling with gas the vent would take liquid and get blocked, rather than letting air escape the tank.  Got the same reaction - big fuel backsplash.  Recommend looking at all the vent possibilities.

I also noted in that boat that the fuel filler line that went from the cap to the tank was routed with a dip in the line, rather than on a continuously descending slope.  Fuel could gather in that low point (like a trap in a sink) and could also cause a temporary blockage that could cause a backsplash.  

Both were fairly easy fixes, given that you can access the lines and connections.  I reversed the filler neck with the small vent line above the fuel line, and I added a clamp to correct the descent angle of the filler line within the hull.

 

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No fuel allowed to get into any vent lines. Must be a constant upward angle

The large filling gas line MUST be a constant downward angle.

Why can not the hose people be of a better quality ?

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I did a search on the site before I posted and read about both of your problems with filling and possible fixing.  Problem here is dealer says there is no vent line.  Supposed to be built into the fill. Was wondering if any other members with new boats have this problem before.  I found a vent on the side of the boat that is recessed all the way in and a tube coming from it runs into a black box and that is as far as I got. It looked to me like a recessed gas vent but I didn't dig too far into it.

Al

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30 minutes ago, alka2710 said:

I did a search on the site before I posted and read about both of your problems with filling and possible fixing.  Problem here is dealer says there is no vent line.  Supposed to be built into the fill. Was wondering if any other members with new boats have this problem before.  I found a vent on the side of the boat that is recessed all the way in and a tube coming from it runs into a black box and that is as far as I got. It looked to me like a recessed gas vent but I didn't dig too far into it.

Al

that is your vent as it is a carbon/charcoal filter.  If that is not working properly then you could have slow filling and/or burping gas.  Others have had issues with those filters as they do get clogged.  One thing is for sure is you never want to overfill your tank.  Once the pump clicks off stop and do not continue to fill it. 

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That black box is the charcoal canister that is required by the EPA to be installed on 100% of all new boats manufactured after July 31, 2012. These systems are designed to control diurnal emissions (when the fuel expands and contracts due to temperatures) and prevent the release of hydrocarbon emissions when fueling.   They sound great in design but in reality that can be a nightmare!  I know from experience.  Here is the problem.  The recessed (flush) p-trap vent on the hull has internal baffles which are designed to limit water intrusion during normal operating and washdown procedures.  The barb on the p-trap points downward at 90 degrees and is connected to a vent line that runs into the black box.  Unfortunately water DOES get into the p-trap and since there is no upward loop the water goes directly into the charcoal canister, clogging the system and essentially blocks the vent.  The fuel fill hose does not have a vent built into it so now you have a pressure lock in the system and cannot add fuel because the system cannot release the vapor in the tank (the fill hose also has an inlet control valve that springs shut upward so no way is gas getting in now.

I have a 2015 21' H20 sport and had this problem twice in one year (less than 45 hours).  At first they thought it was fuel getting into the canister but the 2 valves on the tank (fuel limit and grade valves) are designed to only let vapor pass though the vent and not liquid.  Last week they found my canister full of salt water.  They replaced the canister and after discussing the issue with Chaparral and the fuel system manufacturer (Attwood marine) they rectified the issue by turning the p-trap around so the barb now points 90 degrees upward AND they added a longer vent hose with an upward vertical loop to prevent the water that does make it through the p-trap  from getting into the canister and it can drain out (they call this a tortuous path).  I spoke with Attwood directly (awesome customer service) and they told me that they have had over 1500 logged issues with water getting into the canister and preventing fueling.  For the bigger boats, the p-trap may be higher above the waterline but in my H20 it was about 12-14 inches above the waterline (below the run rail).  Poor design for sure. 

There have been reports on other forums of people putting clear tape over the vent while running (I would never do that) or installing a clam shell over the vent.  The problem is not limited to Chaparral but with our boats the issue is more common with the smaller boats and the vortex boats (especially when ballast is added to the vent side!).

Your friend should contact the dealer to get this fixed the right way.  For a quick fix, you can disconnect the canister, pour out the water and let it  dry.  it will work again when dry but may not be as effective removing the hydrocarbons from the vapors (sorry EPA). 

New H20 owners - does your p-trap have an upward loop n the vent line?  The 2016 models may have had this corrected at the factory.

Good luck

 

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Get in there and check the hoses into the canister. We find spider nests in the vent hoses at times. surprising how much pressure they can hold. Also check for any kinked over vent lines. Raw fuel in a line can also cause the issue as well as a saturated canister.

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Thank you HunkerDown.

Nice explanation of the  latest thing causing slow refueling.

The E P A is staffed ONLY with people who have the same genes as the mayor on the Dukes Of Hazzard. The mayors verbal solution to any problem was.

Handle it. Handle it.  The mission of the E P A.

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7 hours ago, HunkerDown said:

That black box is the charcoal canister that is required by the EPA to be installed on 100% of all new boats manufactured after July 31, 2012. These systems are designed to control diurnal emissions (when the fuel expands and contracts due to temperatures) and prevent the release of hydrocarbon emissions when fueling.   They sound great in design but in reality that can be a nightmare!  I know from experience.  Here is the problem.  The recessed (flush) p-trap vent on the hull has internal baffles which are designed to limit water intrusion during normal operating and washdown procedures.  The barb on the p-trap points downward at 90 degrees and is connected to a vent line that runs into the black box.  Unfortunately water DOES get into the p-trap and since there is no upward loop the water goes directly into the charcoal canister, clogging the system and essentially blocks the vent.  The fuel fill hose does not have a vent built into it so now you have a pressure lock in the system and cannot add fuel because the system cannot release the vapor in the tank (the fill hose also has an inlet control valve that springs shut upward so no way is gas getting in now.

I have a 2015 21' H20 sport and had this problem twice in one year (less than 45 hours).  At first they thought it was fuel getting into the canister but the 2 valves on the tank (fuel limit and grade valves) are designed to only let vapor pass though the vent and not liquid.  Last week they found my canister full of salt water.  They replaced the canister and after discussing the issue with Chaparral and the fuel system manufacturer (Attwood marine) they rectified the issue by turning the p-trap around so the barb now points 90 degrees upward AND they added a longer vent hose with an upward vertical loop to prevent the water that does make it through the p-trap  from getting into the canister and it can drain out (they call this a tortuous path).  I spoke with Attwood directly (awesome customer service) and they told me that they have had over 1500 logged issues with water getting into the canister and preventing fueling.  For the bigger boats, the p-trap may be higher above the waterline but in my H20 it was about 12-14 inches above the waterline (below the run rail).  Poor design for sure. 

There have been reports on other forums of people putting clear tape over the vent while running (I would never do that) or installing a clam shell over the vent.  The problem is not limited to Chaparral but with our boats the issue is more common with the smaller boats and the vortex boats (especially when ballast is added to the vent side!).

Your friend should contact the dealer to get this fixed the right way.  For a quick fix, you can disconnect the canister, pour out the water and let it  dry.  it will work again when dry but may not be as effective removing the hydrocarbons from the vapors (sorry EPA). 

New H20 owners - does your p-trap have an upward loop n the vent line?  The 2016 models may have had this corrected at the factory.

Good luck

Very nice replay thank you I will forward it to my friend

Al

 

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On 8/11/2016 at 10:27 AM, alka2710 said:

Friend has a 2016 250 Suncoast and no matter how we fuel her up at the station or with gas cans and a shake and siphon we get a major gas back splash.  Always thought this was a venting problem.  Any tips or suggestions.

Al

We had the same problem on our 2016 264 Sunesta. Was one of the issues taken care of at the 20 hr. service.....dealer said they it was slack in the filler hose.....fills fine now.

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I had the same problem on a 27sig. My fuel fill line had a dip when trying to fill with a gas can fuel would build in the dip and because there was no pump pressure to push it past the dip it would splash back. The fix was 4 11" sip ties to secure the fill lines in a down wood position. Problem sloved

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