Northriver gas venting problems

[TyeeTom]

I'm interested if there are any NR Mariner owners that have gas tank venting problems similar to mine. As many of us found out the hard way, these boats must be stored bow-up to prevent gas from spewing out the filler cap and/or vent during hot days. My first Mariner, and '02, did this and it could be managed.

However, my new Mariner has far worse problems. First, it takes fuel very slowly, taking around 10-15 minutes for 6-8 gallons. All the while, dripping fuel out the vent. And when it's stored in my garage, bow fully elevated, and 8+ gallon LOW on fuel, on a warm day (70 degrees), fuel comes out the vent.

Any of you out there have similar problems? Know of a fix? I've discussed the problem with NR and they say bring it in and they will look at it. But I want to know if this is a chronic problem. Anyone?

[Jooky]

it takes you an hour to fill your tank?

[Jason S]

I have to fill mine with the bow elevated and was told this when I bought it. If the bow is not elevated it will "burp" out the filler. otherwise will take fuel at full flow of the pump. I can get mine totally full also.

[TyeeTom]

Yes, based on the time it takes to put in a few gallons, I'd be at the gas station quite a while trying to fill it from empty.

The bow is also elevated when trying to fuel it. At first, it only takes a few gallons and then seems to be full. Honestly, I'm not sure I've got it full. Can't really tell for sure with the venting problems. And the fuel gauge has never worked and always shows full, even when on the water and down 8-10 gallons. ...but I digress....

This is not the simple, "elevate the bow" problem......"

[6wapiti6]

I have an "04 Mariner, and I have had the same problems. At first I thought it was just to full and the heat caused the overflow. Than a few weeks ago the boat had about 3/4 of a tank and the weather was barley 70 and I noticed gas coming out? I've been able to stop it by lowering the bow though, not raising it. I had one issue when trying to fill, but have since been ok. Oh, I never trust the gauge and always am sure to put in fuel before each use.

[backlash442]

I have an 02 Seahawk and have some similar issues when filling up. Gas will vent out even when not full. Have to go pretty slow. Although I don't have a problem with gas venting out when hot. Then again I never leave much gas in due to people liberating it.

Is your vent in the back on the transom? Mine is just below the transom on the starboard side.

[Flatfish]

Have you contacted the maker, and asked them their advice?

MATD

[Magnum]

When I had my '04 Mariner, I had to have the bow down. Never leaked at all when the bow was down, even on a full tank...mid-summer. Bow up, gas everywhere. My boat had the vent in the rear of the tank. :shrug:

[fish_on]

Had the same problem with my Sea Hawk. NR took care of the problem, it was a vent hose routing issue and now it fills fine. There are a few devices you can put in-line of you vent to keep the fuel from coming out. Look back a few days and there was a thread about this same thing and a link to some solutions. Talk to NR about the fill issue they can fix that.

[Tacklebuster]

Do you have the Attwood gas cap with built in vent (plastic) or a screw on gas cap with a seperate vent?

I had both and the only issue I had with the seperate vent that was in the back was it took forever to fill up. I took it back and they re did the vent line and all was well. If you have the Attwood type cap, just be glad fuel is all your issues.

My boat, and any boat will spill gas out of the vent hole if 3/4 full and left out in the sun.

[River Bum]

I don't have a mariner, but sounds like you are blocking your vents when parking bow up. Try it the other way. When hooked to your truck, if it sits bow up, I would try use a deeper hitch to level it a bit and try fueling. Should make a difference. In my boat, if I fuel at a station the makes me sit bow up, it cuts my fuel capacity by almost five gallons. Your tank is only about 5" deep, so it doesn't take much to block the vent. I always park my boat full of fuel and, like Magnum said, I'll have gas everywhere if parked bow up.

[fireguy]

I Just had my Mariner in the Northriver shop two weeks ago for the same vent problem. My boat had the fill and vent in the one cap. I had the problem in warm weather and filling at the station with it burping down the side of the boat and removing all the Sharkhide I had just applied. The guys at Northriver replaced the fill cap to the screw-in type and added a vent line to the back of the boat. They also checked the backflow check valve(they said I might want to remove it ?). Well all in all it cost me almost $200, I hope this will fix the problem.

[backlash442]

Fireguy, why would you have to pay for something that seems like it's a North River design issue? If it wasn't then why so many people having problems then?

[fireguy]

I would have to :agree: with you about it being a design problem, but I did buy the used from another person and I know this problem from the previous owner. Another design problem with the boat is the back transom isn't cut-out far enough for the steering arm on the outboard. You can only tilt the motor with it turned to one direction, otherwise the arm that comes out of the outboard will be bent.

[fishgetter]

If I paid that kind of money for a North River I would be thinking about finding another boat builder before I handed over another $200 bones. Just menton to them that you bought the boat for the best fit and finish and leaking gas is not the best. Just my 2 cents.

[Tacklebuster]

Gas is gonna leak through the vent, it's gonna happen. You just need to make sure the only leak is gas and it's coming out of an area that isn't ruining your boats paint. A vent in the back of the boat is a "no brainer" in my opinion that will allow gas to vent into a bucket or something if you have your boat out in hot weather and a 3/4 or more full tank.

[backlash442]

Yup gas will leak from any vent under the right circumstances. However, it would appear that there was some sort of problem with the way that North River designed the vent in the first place. Hence people taking their boats in and getting them fixed.

I bought my North River used as well but from one of their dealers. I was told there was no warranty but if there was a problem that was an obvious defect the manager told me they'd fix it. My boat does have the problem filling up (gas spilling out way before full) but it's not that big of a deal to warrant me to get fixed (if indeed it really needs to be done). Neither is the porposing. Which North River said they'd fix. Even with a used boat North River went out of their way and sent me a complete axle at no cost when mine went out a few months after I bought the boat. Something that they did not have to do. So it does surprise me when I read that people have to pay to get certain things fixed.

[TyeeTom]

Good info from you all. Here's a question.

Boat is 2/3's full of fuel
Stored fully bow up
Garage temp 75 degrees
Fuel seeping from vent

When I open the gas cap, it's pressurized, ie, air blows out the cap.
If it's vented correctly that shouldn't happen, should it?

[R Jackson]

Good info from you all. Here's a question.

Boat is 2/3's full of fuel
Stored fully bow up
Garage temp 75 degrees
Fuel seeping from vent

When I open the gas cap, it's pressurized, ie, air blows out the cap.
If it's vented correctly that shouldn't happen, should it?


The following assumes the tank is at the stern of your boat. You should really try storing it with the bow down. When you store it with the bow up, all the fuel moves towards the back of the tank, blocking the vent opening from the tank. As the fuel expands, it will take the path of least resistance up and out of your vent. When your boat is bow down, the fuel has moved towards the front of the tank. Now there is an air pocket where the vent enters your tank. As the fuel expands, air and fuel vapor will be pushed out of the tank. If you have the energy to do it, I would remove your floorboards and trace your vent line from the exit to the tank. Make sure your vent line doesn't drop below the top of your fuel tank. That would create a low spot trapping gas in the vent line. Hpoe that helps.

[WaterDog]

Most belly tanks fill and vent from the rear of the tank. When you fill and store it put the bow DOWN just like R Jackson said.

Pull the floor up and see for yourself how the tank is vented.

[SouthCoastStu]

I don't know about NR, but on my Alumaweld the vent line is all the way forward on the gas tank. The vent line runs back to the fill cap (back corner of the boat) the fill line goes into the back of the tank. This way no matter which end of the tank the air bubble goes to, it can vent to the atmosphere (no pressure). If both the vent and fill where at the back of the tank (not the way I would design it), raising the bow would cause an air bubble to get caught in the tank; as the air heats up it would expand and force gas out the vent or fill tube.

I've never had an issue with gas seeping out, bow down or up. Do have to use a slow fill at the gas station to get that last couple of gallons in though.

[fireguy]

Northriver fuel tanks and can be either vented in the front or the back(some years and models are different). The guys were glade to see that mine was located in the rear, otherwise the floor would have needed to be removed. I was told to store my boat bow down and have my trailer hitch as level as possable to fuel.