Author Topic: 27 gallon gas tank install on 16 SC  (Read 7371 times)

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Offline Fisherdv

Re: 27 gallon gas tank install on 16 SC
« Reply #100 on: November 25, 2017, 01:30:18 PM »
Sounds like those larger tanks have this issue, maybe too much tank area to vent quickly........looks like you will need patience at the pumps.

May not help much but you could chamfer the ID of the filler on your tank, it may cut the splash some when filling :shrug9:
I thought about doing that, but that would involve draining gas and flushing all the shavings out of the tank. 3wt, AJFISHIN has the same tank and vent as I do and his is the older one.
2018, Sea Chaser 16, Honda 60HP

Offline Threeweight

Re: 27 gallon gas tank install on 16 SC
« Reply #101 on: November 25, 2017, 02:46:25 PM »
I think the only difference between the new and old tank is the material (new stuff is alcohol resistant and won't leech anything through the plastic).  From what you are describing, I think you have a vent problem, not a problem with the fill. 

When the motor is running, you are pulling air into the tank (to replace fuel volume) rather than pushing it out (when you fill the tank, replacing air volume with fuel).  The volume exchanged is several orders of magnitude greater when you fill up, as well.  A stuck check valve could explain that, or that vent fitting on the tank itself could be undersized on it's ID due coming out of the mold wrong, or not being cleaned up enough.

As far as the fill goes, as long as the ID of the tank fill fitting is larger than the diameter of the gas pump nozzle at the fuel station, you shouldn't overwhelm the fill.  But if the tank can't vent air fast enough it will cause back pressure and then you slosh fuel out of the fill opening.  On new boats with the pressurize fuel system, this is VERY common problem (don't ask me how I know this.)  My 100 gallon tank uses the same 5/8" transom vent fitting and hose as yours, but has a 2nd vent in the fuel fill fitting itself that lets back pressure out

I'd ask the guys at Arima for their thoughts on Monday.

Former Sea Chaser 17 owner
Wild Card, Hewescraft Ocean Pro 220, Honda 225 and 9.9

“Never turn your back on fear. It should always be in front of you, like a thing that might have to be killed.”
       --- Hunter S. Thompson

Offline Peddler

Re: 27 gallon gas tank install on 16 SC
« Reply #102 on: November 25, 2017, 06:04:41 PM »
Try disconnecting the vent hose from the fitting, and then attempt to fill again.  It'd rule out the fitting being the problem.
Wishin' I was Fishin'

Offline Fisherdv

Re: 27 gallon gas tank install on 16 SC
« Reply #103 on: November 25, 2017, 06:19:38 PM »
Try disconnecting the vent hose from the fitting, and then attempt to fill again.  It'd rule out the fitting being the problem.
I did that only I disconnected the vent hose from the tank side. NOT a smart idea! It filled fast, but it was squirting out that vent hole on the tank.  :doh: On the plus side no problems while running the boat (fished two days now). This seems like a common problem on these Arima/Inca tanks. I guess I’ll either have to think of a fix or just live with a very slow pump time. I think the problem is the size of the vent hole off the tank. 3wt, does your new can also fill slow?
2018, Sea Chaser 16, Honda 60HP

Offline Fisherdv

Re: 27 gallon gas tank install on 16 SC
« Reply #104 on: November 25, 2017, 06:50:12 PM »
@ JChaser, did you say you do not have any problems filling with the same tank and vent? I wonder what’s different?
2018, Sea Chaser 16, Honda 60HP

Offline AJFishin

Re: 27 gallon gas tank install on 16 SC
« Reply #105 on: November 25, 2017, 07:13:59 PM »
It sounds like that hole is to small and not allowing enough air to escape the tank when you're filling up.
Did you measure the vent hole? If it's a small diameter maybe run the gas out and drill out the vent hole some.
I had to siphon gas out of my tank one time, not hard to do. Bought a 5 gallon tank at Harbor freight and put the gas in my truck.
My thoughts on drilling it out. Lay the tank on the side, stick a shop vac hose inside to collect the shavings.
I know it's a PITA, but just a thought. :shrug9:
'96 Sea Chaser 16 - Yamaha 70HP - 2 smoke

! Go Kings Go !

Offline Fisherdv

Re: 27 gallon gas tank install on 16 SC
« Reply #106 on: November 25, 2017, 08:48:28 PM »
Ya that would be a PITA to take it out again. Maybe when it comes time to clean out the bilge or something. I’m afraid if I drill out the vent it may get to thin and collapse when lightly clamped, not sure though it is kinda thick. My vent hole looks about the same as yours. Just by looking last night I would guess 3/8 or so. Funny that JChaser has the same setup as we do and he said he has no problems. Maybe your right about the Chevron pumps? It’s really the only good grade gas near me. There’s a few no name gas stations but I don’t trust the gas
2018, Sea Chaser 16, Honda 60HP

Offline Yachter Yat

Re: 27 gallon gas tank install on 16 SC
« Reply #107 on: November 25, 2017, 08:52:15 PM »
    I think your going to find the openings on these vents are too small to handle "all" of the venting required when filling.............that is, unless filling takes place very slowly.  You don't want to block the filler too much when fueling. When I fill my tank, it seems like much of the venting takes place back up the filler neck.  Before making any modifications to the tank, I would experiment with the nozzle placement and see what happens. 

Yat
Dear Arima:  Please "square-off" the Hunter transom.  Make it like my old 77 Silverline.  Thank you.  Oh yeah...please hurry; I'm getting old.

16 SC/Honda 60

Offline Fisherdv

Re: 27 gallon gas tank install on 16 SC
« Reply #108 on: November 25, 2017, 09:00:04 PM »
You know, I did play with the nozzle placement and even pulled back the boot by hand and held the nozzle a bit higher so there would be some venting out the filler but no help. Maybe the flowing gas seals it off and doesn’t allow venting. By the way I should be officially a “fisherman” now after this post!  :gone_fishing:
2018, Sea Chaser 16, Honda 60HP

Offline Fisherdv

Re: 27 gallon gas tank install on 16 SC
« Reply #109 on: November 26, 2017, 12:43:37 AM »
AJFISHIN, after comparing the pics of your tank vent vs. mine yours does appear to have a bit larger hole. Maybe I do need to drill it out just a bit to at least 3/8. If so I’d really like to do it without draining and removing the tank. I could hold a vacuum to it while drilling and hope it catches all the shavings, but if not the fuel filter shouldn’t let the particles through. I could change the filter after a couple tanks? This may well be the problem

2018, Sea Chaser 16, Honda 60HP

Offline Yachter Yat

Re: 27 gallon gas tank install on 16 SC
« Reply #110 on: November 26, 2017, 06:17:53 AM »
   Yes, I suppose you could drill-out the tank vent, but I wouldn't open so much that the wall of that tank vent stanchion gets too thin.   Then, there's still the question of the opening inside the vent fixture itself, I guess.  I must admit, this one is a bit perplexing. 

Yat
Dear Arima:  Please "square-off" the Hunter transom.  Make it like my old 77 Silverline.  Thank you.  Oh yeah...please hurry; I'm getting old.

16 SC/Honda 60

Offline Threeweight

Re: 27 gallon gas tank install on 16 SC
« Reply #111 on: November 26, 2017, 09:33:04 AM »
I did that only I disconnected the vent hose from the tank side. NOT a smart idea! It filled fast, but it was squirting out that vent hole on the tank. 

If it filled fast, that would seem to indicate your problem isn't the diameter of the vent fitting.  The diameter is the same whether the hose is attached or not.  I'd suspect either the hose or the P-trap.

My new boat's tank was designed to operate under pressure... 1 PSI required in the tank before it will vent.  It has a vent on the stern like yours, then a second vent under the fuel cap.  Fuel cap vent is supposed to let the tank vent freely when the cap is off at the fuel pump.  It "mostly" works... I can pump 50-60 gallons in as fast as the pump will put it out, but the last 10-15 gallons is a giant PITA. 
Former Sea Chaser 17 owner
Wild Card, Hewescraft Ocean Pro 220, Honda 225 and 9.9

“Never turn your back on fear. It should always be in front of you, like a thing that might have to be killed.”
       --- Hunter S. Thompson

Offline Croaker Stroker

Re: 27 gallon gas tank install on 16 SC
« Reply #112 on: November 26, 2017, 11:29:37 AM »
Try taking off the P-trap and stick the vent hose out the hole into the motorwell. If it fills fast, then you found the culprit.

Looks like there is some sort of screen/filter in those contraptions. If it gets wet with fuel, it might not pass air or gas.
« Last Edit: November 26, 2017, 11:35:35 AM by Croaker Stroker »
1987 - 17' Sea Pacer - 2004 Evinrude 90 E-tec
15' Sea Sprinter - **SOLD**

"If a fish will, he will… if he won't, he won't… and that's about it… except… he may take this when he won't take that."

Offline blindmonkey

Re: 27 gallon gas tank install on 16 SC
« Reply #113 on: November 26, 2017, 11:45:22 AM »
Both Peddler and Croaker have suggested removing vent hose from fitting and see if problem is resolved. I would do this before doing anything else to the tank.
Lorne
2013 17' Sea Chaser, Honda 90, Yamaha F8
1994 Sea Explorer, Mercury 60, SOLD

Offline Fisherdv

Re: 27 gallon gas tank install on 16 SC
« Reply #114 on: November 26, 2017, 02:07:58 PM »
Ok, I will try that at next fill up. I tried disconnecting the vent hose from the tank and I can blow air through the vent
« Last Edit: November 26, 2017, 02:17:38 PM by Fisherdv »
2018, Sea Chaser 16, Honda 60HP

Offline AJFishin

Re: 27 gallon gas tank install on 16 SC
« Reply #115 on: November 27, 2017, 12:52:33 PM »
Both Peddler and Croaker have suggested removing vent hose from fitting and see if problem is resolved. I would do this before doing anything else to the tank.


Also just a thought if that works, maybe you need to get a different vent or exchange the one you have ?
I've seen online some people that are using the Attwood 66023-1 or Premier Boat Fuel Vent 7000-2164 (or something similar), and then added  inline, which is expensive, a Racor Fuel/Air Separator LG50.
I know it's expensive, maybe not worth it, and not sure if this is something that would be better then what you currently have. But it's just thought and I figured I'd toss it out there and see what the consensus is.  :shrug9:
 
'96 Sea Chaser 16 - Yamaha 70HP - 2 smoke

! Go Kings Go !

Offline Fisherdv

Re: 27 gallon gas tank install on 16 SC
« Reply #116 on: November 27, 2017, 02:39:21 PM »
If that would solve my problem I would pay the money for it. Not sure though, what’s funny is that I have no problem with me blowing air through the vent hose with the Atwood p-trap still on. Maybe it’s restricting just a bit to much but I don’t notice it. That racor LG50 may also restrict air flow. Anything labeled EPA compliant or let’s less vapor in the air has to be restrictive in some way. Most EPA compliant portable tanks don’t vent at all and swell up like balloons. I’m gonna try though as a last resort taking the p trap vent off and filling with a straight open vent hose. Gas will probably end up spitting out that hose though! :doh:
2018, Sea Chaser 16, Honda 60HP

Offline Threeweight

Re: 27 gallon gas tank install on 16 SC
« Reply #117 on: November 27, 2017, 03:20:59 PM »
I would also emphasize again making sure you have no low point of any kind to trap fuel.  Snagged this graphic off The Hull Truth... this shows the fill line, but the same thing applies to the vent line.



You want it like this (minus the dumb little fuel whistle):

Former Sea Chaser 17 owner
Wild Card, Hewescraft Ocean Pro 220, Honda 225 and 9.9

“Never turn your back on fear. It should always be in front of you, like a thing that might have to be killed.”
       --- Hunter S. Thompson

Offline Fisherdv

Re: 27 gallon gas tank install on 16 SC
« Reply #118 on: November 27, 2017, 03:24:53 PM »
I did that only I disconnected the vent hose from the tank side. NOT a smart idea! It filled fast, but it was squirting out that vent hole on the tank. 

If it filled fast, that would seem to indicate your problem isn't the diameter of the vent fitting.  The diameter is the same whether the hose is attached or not.  I'd suspect either the hose or the P-trap.

3wt, if with the vent hose disconnected at the tank and while filling with an almost empty tank and fuel was squirting out the vent hole on the tank (no hose) wouldn’t that indicate the hole is to small and too much pressure is building up? How can the fuel with a near empty tank travel about 12 inches up and out that vent hole if not? I would think with a larger vent hole the fuel would stay down? Kinda like filling a portable tank with the cap off?
2018, Sea Chaser 16, Honda 60HP

Offline Fisherdv

Re: 27 gallon gas tank install on 16 SC
« Reply #119 on: November 27, 2017, 03:26:45 PM »
I would also emphasize again making sure you have no low point of any kind to trap fuel.  Snagged this graphic off The Hull Truth... this shows the fill line, but the same thing applies to the vent line.



You want it like this (minus the dumb little fuel whistle):


mine looks like the bottom picture, see the pics earlier on
2018, Sea Chaser 16, Honda 60HP

Online Danno

Re: 27 gallon gas tank install on 16 SC
« Reply #120 on: November 27, 2017, 03:57:33 PM »
That vent hole coming off of the tank seems awfully small. Click on the picture to make it straight I don’t know why they always come out sideways

Just a side note on how these tanks are manufactured: They are made via rotation molding which involves pouring flakes of plastic into a mold and rotating the mold while heating until the plastic melts and forms a solid wall. The outside dimensions will be that of the mold but the inside dimensions are based on how much plastic they added to the mold. Being a gas tank, I suspect that they may measure the tank's wall thickness to ensure enough material was introduced to the mold but I seriously doubt that they would check the wall thickness around the vent.

You photo shows that it's much thicker in the vent than it likely is around the rest of the tank's walls. I don't know if this is your problem but I would open that vent up
Previously owned a 1998 19' SR

Lures are designed to catch fishermen not fish.

Online Chief of the Boat

Re: 27 gallon gas tank install on 16 SC
« Reply #121 on: November 27, 2017, 04:43:09 PM »
Danno's post is spot on the conversation I had with Don on how the tanks are made and his solution. 
1994 Sea Explorer 1511 loves whitecaps 2010 Yamaha F-70 2012 Yamaha F-8 with a  Fixed SaltBoss Bracket Lowrance HDS-5 & 7 Gen 2 Standard Horizon Fixed VHF 2150 with AIS

Offline Fisherdv

Re: 27 gallon gas tank install on 16 SC
« Reply #122 on: November 27, 2017, 04:43:53 PM »
That vent hole coming off of the tank seems awfully small. Click on the picture to make it straight I don’t know why they always come out sideways

Just a side note on how these tanks are manufactured: They are made via rotation molding which involves pouring flakes of plastic into a mold and rotating the mold while heating until the plastic melts and forms a solid wall. The outside dimensions will be that of the mold but the inside dimensions are based on how much plastic they added to the mold. Being a gas tank, I suspect that they may measure the tank's wall thickness to ensure enough material was introduced to the mold but I seriously doubt that they would check the wall thickness around the vent.

You photo shows that it's much thicker in the vent than it likely is around the rest of the tank's walls. I don't know if this is your problem but I would open that vent up
The vent hole AND the filler hole are both much thicker than the rest of the tank. If all else fails I may have no choice
2018, Sea Chaser 16, Honda 60HP

Offline Fisherdv

Re: 27 gallon gas tank install on 16 SC
« Reply #123 on: November 27, 2017, 04:52:51 PM »
Danno's post is spot on the conversation I had with Don on how the tanks are made and his solution. 
So is Don recommending drilling out the vent hole some? That would be difficult to not get shavings in the tank.If I held a vacuum while I drill it might not be a good idea to suck fuel fumes though a vacuum motor, even with the tank drained, I’m sure there would be a lot of fumes :shrug9:
2018, Sea Chaser 16, Honda 60HP

Offline Threeweight

Re: 27 gallon gas tank install on 16 SC
« Reply #124 on: November 27, 2017, 05:05:03 PM »
3wt, if with the vent hose disconnected at the tank and while filling with an almost empty tank and fuel was squirting out the vent hole on the tank (no hose) wouldn’t that indicate the hole is to small and too much pressure is building up? How can the fuel with a near empty tank travel about 12 inches up and out that vent hole if not? I would think with a larger vent hole the fuel would stay down? Kinda like filling a portable tank with the cap off?

Gas is going to splash and foam from the 2-3' drop from the fuel pump nozzle to the liquid fuel in your tank.  That's going to get fuel up into your vent hose, which is why you want the vent mounted as high as possible, and the hose as vertical as possible to ensure no opportunity for fuel to pool and block venting.  If you pumped gas into the tank with no vent hose attached, it makes sense that it would splash/squirt fuel up out of the vent.

I don't think it hurts anything to ream out the vent opening a bit, other than some concern about plastic shavings going into the tank. 

Another factor maybe worth considering is what angle the boat sits at when on the trailer at the fuel pump.  If it sits at an angle with the nose down, that could cause issues with fuel splashing back up through through the fill and vent with both of them located at the front of the tank.
Former Sea Chaser 17 owner
Wild Card, Hewescraft Ocean Pro 220, Honda 225 and 9.9

“Never turn your back on fear. It should always be in front of you, like a thing that might have to be killed.”
       --- Hunter S. Thompson