Oil Tank and Fuel Vent

[tdonoughue]

Howdy.

Today I could not get any fuel into my tank. The hose filled up and it came right back at me. I pulled apart the check valve and found pretty high pressure in the tank (which I am figuring was holding the check valve shut). Haven't yet found anything in the fill pipe hose (still need to recheck that, @Scottintexas ). So I am now suspecting that there is an issue with the vent system.

Looking at the schematics, I see that the vent from the side of the boat goes down to an 'oiltank'. All I can think is that this is what they are calling the breather system that catches gas fumes. Anyone played with this? Know what it is? Do they go bad?

Hints welcome.

 

[Neutron]

I would assume its a charcoal canister of sorts to filter the fumes. Doubt it would clog but i guess anything is possible. If it was overfilled often enough to get it wet with fuel it could ruin it.
Can you blow air down the vent?
Do you get mud wasps there. Over here they will clog up any small opening

 

[tdonoughue]

Yes, normally I would assume a charcoal canister as well.... So I will be interested to see. I don't think I have overfilled... like at all, no less frequently, but I guess anything is possible.

Haven't tried to blow air down the vent yet--now have that on the list.

We do get mud wasps, but there is a screen at the top of the vent line. I pulled that out already and it is clear.

Hopefully will be able to get back up to the boat tomorrow or so and start taking things apart...

 

[tdonoughue]

Slight update:

When I was up yesterday at the boat, I found that the soundproofing mat I had installed on the hatch to the fuel tank had failed. Adhesive came loose and the mat dropped onto the tank:


On examination (before removing the stuff and trying to clean up the goo), it does not appear that the mat was squishing any of the vent lines. You can see the one running from the middle bottom of the pic off to the right and one on the left side running from the tank up under the mat. While it doesn't look like they were squished, they certainly may have been. Nonetheless, diagnosing to be continued (after I finish cleaning up more goo--that crap got everywhere).

(and yes, I need to clean up some wires someday)

 

[Russell]

Now that's a hot mess! Now I'm a bit worried as I used this type of soundproofing on my engine hatch. What's the product your using here?

 

[tdonoughue]

Yes, it's bad. I had it on the engine hatch, too. Dropped onto the engines.... 'Leaked' down onto the hatch latch. Goo everywhere.

I don't remember the brand (actually bought the stuff 5+ years ago; only installed it during COVID finally), but I think I still have a square or two to remove, so I will have to look.

 

[Russell]

I used the Noico black soundproofing mat. I may have to shield it against heat.

 

[tdonoughue]

@Russell , first, the offending mat:

Brand: Kno Knoise

So, then, back to our original problem, which I am sure @Scottintexas remembers well. Now having removed enough of the tar stuff, I was able to get to diagnosing the vent system. I started back at the vent itself and traced the vent hose forward, thinking first that I must have kinked it or crushed it or something. Here is a pic from the aft port storage, in which you can see the 'canister' (which they say is a oiltank), as well as the route of the hose:

At the hull wall, there is a little almost-right-angle fitting you can't see here. However, suffice to say, I found no kinks or impediments tracing the route from the hull, though into the engine compartment, and back to the tank. Here you will see where the hose comes from the lower right and comes to that middle fitting. When I got to this point, you can see that I loosened the hose clamp at that middle fitting.


I thought I would start here. I pulled off the hose (turned off the radio so I could hear well) and blew into the hose. I heard liquid spewing out. Going to the back to the vent, I found a very decent amount (1/2 gal?) had come out of the vent!


I did investigate; it was water. Apparently somehow (rain? condensation?) the vent pipe, maybe into that oil thingy, came to be so much that it was preventing the venting from the tank.

Weather was foul, so I did not go to try to fill up just yet. Nonetheless, I think the problem is located and hopefully solved.

 

[FSH 210 Sport]

I was initially going to suggest the charcoal canister (oil tank) was full of gas, but it seems you found water in there. These canisters filling with gas has been a problem on street legal dirt bikes.. once full the bike doesn’t run right. Our boats are a bit different from the dirt bike ones as the dirt bike ones have a very small vacuum line going from the canister to the intake manifold after the throttle body to keep them cleared out.

If it was me, I’d pull the charcoal canister and make sure all the liquid/ water is out of it and the vent lines, more than likely it is toast so a replacement may be in order. The activated charcoal in the canister helps to reduce photo reactive emissions aka gas vapors.

Id wager a guess that water was from condensation built up over time, many washings over time or a helper sprayed the hose right on it for a while.

Still, glad you found the problem!

 

[tdonoughue]

Coda:

Blowing it out did not fix the problem. I did wind up ordering a new canister and installing it. Pretty simple install... Remove the forward and aft hoses, unscrew... put the new one in place, screw it on, put hoses back.

Had it out for the second time over Memorial Day and filled it up again. Now it fills like normal. Problem solved.

Of course, as I was filling it, the pump clicked off and I waited a sec and put a bit more in. As I was going through that I realized... I was probably regularly overfilling it that way, which is probably what caused all of the contamination in the canister. Duh.

Moral: Don't overfill your boat, folks.

 

[212s]

Moral: Don't overfill your boat, folks.

It actually says that in the manual - not to "top off" when filling, likely for this type of issue.
Same issue with RAM trucks using the cap-less fill nozzle - manual says do not "top off" after the fuel handle kicks off as fuel can fill up the vent canister and prevent venting which makes fueling difficult.

 

[tdonoughue]

Well, I did say, "Duh." Actually knew that. And when I fill the car and the truck, I hang it up when it first clicks off. For some reason, I have not done that with the boat. Duh.

 

[212s]

Well, I did say, "Duh." Actually knew that. And when I fill the car and the truck, I hang it up when it first clicks off. For some reason, I have not done that with the boat. Duh.

Ha...I missed the "duh" part...my bad.

It's amazing the number of people who don't read the manual at all, and then wonder why things break or don't work right or they have to get service done because they didn't maintain the vehicle or boat or whatever. Simple things like regular maintenance intervals are so easy to find in the owner's manual.

 

[Beernut0875]

Coda:

Blowing it out did not fix the problem. I did wind up ordering a new canister and installing it. Pretty simple install... Remove the forward and aft hoses, unscrew... put the new one in place, screw it on, put hoses back.

Had it out for the second time over Memorial Day and filled it up again. Now it fills like normal. Problem solved.

Of course, as I was filling it, the pump clicked off and I waited a sec and put a bit more in. As I was going through that I realized... I was probably regularly overfilling it that way, which is probably what caused all of the contamination in the canister. Duh.

Moral: Don't overfill your boat, folks.

tdonoughue, do you happen to have the part number or a way to look up the canister? I'm having the same issues and will replace it to see if this remedies the issue.

 

[zipper]

tdonoughue, do you happen to have the part number or a way to look up the canister? I'm having the same issues and will replace it to see if this remedies the issue.

Try here. 2019 Yamaha 242 LTD S E-SERIES (SAT1800FU) Fuel Tank | Yamaha Sports Plaza but first I would make sure mud dobbers have not laid eggs in the screen of the vent.

 

[Beernut0875]

Excellent, most appreciated. On the vent, should I be able to blow into the vent from the outside of the boat? Or is this a one-way from the tank to the outside? no visible obstructions from the exterior of the vent, although I did not try to remove the port that is mounted.

 

[FSH 210 Sport]

Excellent, most appreciated. On the vent, should I be able to blow into the vent from the outside of the boat? Or is this a one-way from the tank to the outside? no visible obstructions from the exterior of the vent, although I did not try to remove the port that is mounted.

The vent flows both directions…

 

[tdonoughue]

Yep. And part 11 at the link @zipper provided. Easy install, but need to crawl in there...

 

[David Martin]

Hey guys not trying to steal the thread but I was looking up this part trying to figure out how it works and the proper operation. When I got my boat almost 4 years ago I could not find how to operate the vent .........I at first took the Allan wrench and opened it to fuel and closed it after fueling. I gradually stop doing that and have not opened it in 3 years.............It fuels just as quick with it open or closed and the performance of engines does not seem to change open or closed.

Any clues as on how it should function.?

 

[FSH 210 Sport]

It’s just a bi directional vent for the fuel tank with no check valves. There is a screen underneath that allen head screw you were pulling off to keep debris out of the tank. It’s good that you checked it as sometimes insects can build their nests in the screen plugging it and restricting air flow.

All air / vapor that flows into or out of the tank passes through a charcoal canister, when the tank vents towards the atmosphere this vapor which is rich with gasoline passes through the charcoal canister where the granular charcoal traps a lot of the gasoline vapor, when fresh air flows into the tank, the gasoline laden charcoal grains releases this trapped gasoline and is carried back towards the tank. The purpose of the charcoal canister is to prevent, as much as possible, gasoline vapor from becoming photo reactive with the sun.

Additional; Photo reactive hydrocarbon vapors in the form of gasoline and oil vapor from crank case breathers in the 50’s, 60’s, and early 70’s is what caused the majority of smog in So Cal where I grew up, if you didn’t grow up in a metropolitan area in the 50’s 60’s & 70’s you have no idea what bad air quality is. The first significant emissions device was the PCV or positive crank case ventilation where in a tube was run from the crank case vent to the base plate under the carburetor which burned a significant amount of these oily vapors. The next device was the EGR exhaust gas recirculating device that brought in exhaust gas to the combustion process to reduce the burn temp which reduced oxides of nitrogen N3, of course that decreased mpg. The last major emissions device was the catalytic converter that burned the left over / unburnt fuel. Somewhere in the 80’s I think fuel systems on cars began having gas caps that only allowed air into the gas tank and not out which kept those gas vapors in the fuel system and out of the sunlight, and I think it was in the mid 90’s all gasoline pumps in ca started having vapor recovery at on the fill handles at the gas stations. Combine the aforementioned devices with air pumps, closed loop fuel injection and turbocharging and the average car today produces on the order of 90% reduced emissions from the typical car produced in the 60’s. Fun fact, the tier 3 emissions systems with their hydrous ammonia injection or DEF diesel exhaust fluid on modern Diesel engines are so clean that in high density cities the exhaust that comes out of these engines is cleaner than the surrounding air.