Slow Fueling

[Last Stop]

As we discussed above, you have the newer style "EPA" system that, while the guy at the EPA sitting behind desk thinks it makes everything better... the rest of KNOW it does not!

If you haven't already, be sure to read through the entire thread. I'm not sure if we talked about this, but bypassing the charcoal canister is a temporary way to diagnose if the EPA system is at fault. Sometimes these "temporary" fixes become permanent....

Yes, you can remove that vent cap and check/clean the filter. FYI, this was mentioned early on in the thread, as well.

Is this the filter?
Photo from behind vent.
the vent screen is clean.

 

[DennisG01]

If, by "filter", you're referring to the carbon canister filter... no, that is not it. It is much larger. follow the vent line from there (or from the tank) and you'll find it.

 

[Last Stop]

If, by "filter", you're referring to the carbon canister filter... no, that is not it. It is much larger. follow the vent line from there (or from the tank) and you'll find it.

Thanks

 

[Last Stop]

As we discussed above, you have the newer style "EPA" system that, while the guy at the EPA sitting behind desk thinks it makes everything better... the rest of KNOW it does not!

If you haven't already, be sure to read through the entire thread. I'm not sure if we talked about this, but bypassing the charcoal canister is a temporary way to diagnose if the EPA system is at fault. Sometimes these "temporary" fixes become permanent....

Yes, you can remove that vent cap and check/clean the filter. FYI, this was mentioned early on in the thread, as well.

So I removed the charcoal filter canister on the vent hose and replaced the hose from tank to vent.
NO IMPROVEMENT!!!

 

[Last Stop]

Thanks Guys. I will check further. Putting more gas in it tomorrow.

Your problem sorted?
I removed the charcoal canister and replaced the vent hose with no improvement?

 

[Joefromboston]

I have a 306 Canyon with the same issue. Was wondering if others had to deal with it. Thank you for the background information!

 

[DennisG01]

So I removed the charcoal filter canister on the vent hose and replaced the hose from tank to vent.
NO IMPROVEMENT!!!

OK, so that's actually progress! It shows the EPA system is not clogged. That brings us back to the vent itself, the hose between the vent and the tank fitting and the actual tank fitting. What you wan to do is to check for a clear airway between the hull fitting and the tank. You can do this any number of ways - blowing through one end of the hose or the other is what you're after. And also checking that blowing air into the tank fitting is clear. There must be a clog somewhere in one of those things.

Keep in mind that a "clog" could be a low spot in the vent hose somewhere along the way where excess fuel has collected.

 

[seasick]

Try not to jam the nozzle in too hard and to fill at a slower rate. I know that sounds like a 'DUH' thing to say but it may help.

As Dennis mentioned, a low spot(down loop) in the fuel line will cause gas to pool. Also a high spot (up loop) will also cause gas to back up in front of the loop. Unfortunately it often isn't easy to examine the entire run of the fuel fill hose

 

[SkunkBoat]

I am generally NOT the guy who says "Ask your Grady dealer.." but if I had a brand new 30' Grady and I couldn't put gas in it, I would be a very loud customer.
Luckily, I don't have a new boat.

There is a pretty good thread on THT regarding EPA fuel systems
https://www.thehulltruth.com/boatin...-marine-fuel-tanks-30-reduction-capacity.html

Here is a very interesting picture from that thread.
So what I see it that the main fill vent hose does not go to the canister. The canister and p trap (and thruhull vent) are connected with a smaller hose. When the UNVENTED Fuel Cap is in place, the small vent in the P trap allows for pressure equalization. The Grade valve is also connected with a small hose. Apparently the grade valve helps vent if you are on a trailer and parked on a hill?

The fuel cap is NOT vented. When your cap is removed to fill, the large vent hose comes into play. It is not effected by the canister or p trap at all.
Look at the black things projecting down into the tank. The Vent Valve and Inlet Valve. They are plactic ball float valves that prevent fuel from going up the fill hose and vent hoses.
The vent valve has to be shorter than the fill valve or your vent will close before the fill closes.
These valves reduce the useable capacity of your tank.

So a clogged canister or ptrap SHOULD have no effect on filling the tank.
Now, if your system does not have a large vent hose to the deck fill then you are always screwed.




All of this crap is supposed to reduce the fuel vapor escaping to the atmosphere. But if you are spitting a pint of gas out evry time you fill, its not accomplishing anything.

 

[seasick]

I am not sure I understand the diagram and I will have to take a look at the article. One point that needs clarification is as I see it, when motoring (not gassing up) the vacuum of the gas being drawn out has to be replaces by outside air (vented) since the cap is not vented, that air has to be drawn back from the outside through the carbon canister. If so, a clogged canister can cause the motor to starve for fuel ( I think). When gassing up assuming vapors vent through the canister, a clogged canister would result in higher tank pressure and maybe cause the gas nozzle to trip. Did I miss something in your explanation?

 

[SkunkBoat]

I am not sure I understand the diagram and I will have to take a look at the article. One point that needs clarification is as I see it, when motoring (not gassing up) the vacuum of the gas being drawn out has to be replaces by outside air (vented) since the cap is not vented, that air has to be drawn back from the outside through the carbon canister. If so, a clogged canister can cause the motor to starve for fuel ( I think). When gassing up assuming vapors vent through the canister, a clogged canister would result in higher tank pressure and maybe cause the gas nozzle to trip. Did I miss something in your explanation?

When gassing up, vapors vent thru the large vent hose that goes to the deck fill because the fill cap is off.
now, idk if grady builds them this way. If they only have one hose with a canister then their design REALLY sucks.

 

[Halfhitch]

Just remember, all this extra crap in the newer fuel systems were the work of the Grady White bean counters and their lawyers. You can bet the mechanics didn't lobby to install all that troublesome equipment. It's an effort by the managers to jump through the federal hoops put in their way to show government control and to be able to defend their interest in court should there be a lawsuit. The fuel tank needs a fill hose routed to have a continuous down grade with no kinks for gravity fueling and a vent hose routed in the same manner, except it needs to rise quickly about 6 inches just inside of the through-hull fitting to prevent seawater entering the tank. No low spots allowed. The fitting should be one designed for the job so water slapping the hull can't force water up the tube. It is good form, if you have doubts about whether water is intruding into the fitting while underway, then placing a clamshell over the vent fitting with the closed side angled forward. The ideal set-up, especially if you have a long tank running fore and aft, is having a vent in both ends of the tank.

Once you become the legal owner of the boat you are the guy making the decisions so decide to go back to what worked. Enough of big brother.

 

[DennisG01]

Skunk, I've never seen an EPA carbon canister system like that - interesting. The ones I'm familiar with go: vent fitting on tank... vent line... carbon canister... vent line... hull fitting.

Here's an example of a real system from a real boat (it seems the pic you have might be a generic one?). Note this is from a Sea Ray, not a Grady - but it's representable of the ones I've familiar with.

But, looking at this parts diagram, I forgot about #6. That's a fuel flow control - basically a one-way valve to prevent backflow/spit-up. If Grady uses it, that's another possible source for the problem. Whether it's defective, not oriented correctly or even clogged.

 

[Beyond A Wake]

So EPA has done it to all of us and it is illegal to remove the canister from the vent line...........
Only remedy is to find the optimal spped with which the fuel can be pumped and it is not that fast.
So thank the desk people who imported the system from the Automotive side. Next is going to be catalytic converters like already applied for stern drive inboards. And next is an electric motor with a gas/diesel generator attached for charging the batteries every x hours.

I was fuming when I was detected this new feature for filling.

H

 

[SkunkBoat]

Skunk, I've never seen an EPA carbon canister system like that - interesting. The ones I'm familiar with go: vent fitting on tank... vent line... carbon canister... vent line... hull fitting.

ya Dennis. I'm sure there are different ways its been configured. I've never seen any of it in person cuz I'm poor and can't afford a new boat

I think the diagram from THT is a better setup but certainly costs more.
Honestly, if I had recurring problems I wouldn't hesitate to "repair" it with a vented fuel fill and a straight hose and ditch the check valves.

 

[DennisG01]

Honestly, if I had recurring problems I wouldn't hesitate to "repair" it with a vented fuel fill and a straight hose and ditch the check valves.

Neither would I. I wouldn't even be opposed to doing it pre-emptively!

 

[Last Stop]

My issue still not resolved.


Takes almost an hour to fill 200 gallons.
Both fill and vent pipes blown out with compressed air from the tank end.
Charcoal canister removed.
Im not sure how to resolve.

I now use a lead sinker to wedge the filler lever to the best flow rate that prevents the back flow ‘tripping’ the flow.

 

[seasick]

It is possible that the fill pipe on the tank has a blockage. Often folks loose the paper/plastic cap liner from additive bottles ( like Ring Free) down the hose. In most cases, the liner just settles into the bottom of the tank.
I am nor sure that blowing compressed air into the fill hose would show a partial blockage. The air from the compressor would be higher pressure but low volume.
A better test of the fill hose would be to undo it at the tank. Seal up the tank fitting. Move as best as possible he fill hose away from the fitting on the tank. Use a water hose (preferable with no nozzle) to 'pour' water into the hose to see if it backs up and/or shows reduced flow at the tank end.
You can also try to push a garden hose through the fill hose. If there is a kink in it, you won't be able to get from the tank end to the fill fitting.

 

[DennisG01]

Blowing out with compressed air may not prove anything. Compressed air will easily bypass a partial blockage. If the vent line has a dip in it, compressed air may not eliminate any standing fuel in the low spot as it may drain right back.

Remove the vent hose from the tank. Does it fill faster? You can put a piece of hose on the vent fitting and just hold it up in the air if you're worried about fuel spitting out.

If it fills faster, the issue is with the vent hose. If it still fills slow, the problem is the fill hose.

 

[seasick]

Blowing out with compressed air may not prove anything. Compressed air will easily bypass a partial blockage. If the vent line has a dip in it, compressed air may not eliminate any standing fuel in the low spot as it may drain right back.

Remove the vent hose from the tank. Does it fill faster? You can put a piece of hose on the vent fitting and just hold it up in the air if you're worried about fuel spitting out.

If it fills faster, the issue is with the vent hose. If it still fills slow, the problem is the fill hose.

I have reservations about removing the vent hose at the tank. While refueling, gas vapors will exit the tank through the vent fitting and can accumulate in the bilge. Although, there should not be any spark sources in the bilge, I wouldn't want find out I made a bad assumption. Instead a temporary vent hose might possibly be attached to the tank and routed up out of the bilge.