My Attempt at the Fixing the Horrid Fuel Smell

[Bob Denman]

If you need it... Here's the 2014 setup. PIMS NYC 012.jpg
I think that your idea of getting the vent line higher than the tank, has real merit!

[nhoj]

Here's another picture of the Canister on a 2014. They still have the hoses running over the top of the gas tank.

Evap_Web.jpg

[3 Wheel Addict]

Here's another picture of the Canister on a 2014. They still have the hoses running over the top of the gas tank.

Evap_Web.jpg

But notice in that picture there is no heat shielding on that tank! That's because on the 14 models they solved the heat issue of heating the tank by getting the exhaust away from it! The only reason that canister is back there is because there is no room to put it back near the engine because of the size of the triple and going farther forward would get it back near the heat source, the exhaust! It being mounted higher and reward would help with fuel slosh "possibly" making it's way into the canister.

[gypsy_100]

I am interested in the internals. Were there any valves inside?
I was thinking about cutting in in half, lengthening it, replacing the charcoal and mounting it where the '14's mount.

Mine already has the heat shielding so BRP tried and failed.

pics would be a huge help.

I'll get some up on here later today. Gotta' run.

[Bob Denman]

But notice in that picture there is no heat shielding on that tank! That's because on the 14 models they solved the heat issue of heating the tank by getting the exhaust away from it! The only reason that canister is back there is because there is no room to put it back near the engine because of the size of the triple and going farther forward would get it back near the heat source, the exhaust! It being mounted higher and reward would help with fuel slosh "possibly" making it's way into the canister.

They also had that spot available; because the batteries used to be there...

[jcthorne]

They also had that spot available; because the batteries used to be there...

The 2013 battery is not back there either. Its up front just like the 14. Wonder if the rear mount for the canister would work on the 13? Don't really think it would solve much.

Where is the vent line outlet on the 14? Surely they do not run it back forward and under the engine bay.

[Bob Denman]

They changed to a different fuel tank for 2014...
I believe that 2013 was a "transitional" year. It mixed the current and future hardware.
Which may have been it's "downfall".

[gypsy_100]

No valves, nothing fancy -- just three ports, two chambers and a passageway between them:

canister ports a.jpgtop half from inside a.jpgbottom half from inside a.jpgcharcoal a.jpg

Here's my thoughts on how it functions. The canister is divided into two chambers, about 2/3 and 1/3 -- both filled with activated charcoal. The divider goes from the top to near the bottom but there is a gap at the bottom connecting the two chambers. The tank port and the purge valve port are side by side at the top of the main chamber. The vent port (or drain port) is at the top of the smaller chamber. There is a layer of foam rubber at the bottom that goes under the divider and allows free passage of air or fumes through the foam rubber from one chamber to the other.

When the purge valve is closed (by that I mean not drawing fumes into the engine -- low rpm, idling, not running, etc) the fumes come in from the tank, must go down thru the main chamber, under the divider, up thru the small chamber, and out the port to the long drain hose to the atmosphere. Well and good. Hopefully they get absorbed along the way. Except we know better.

Now, when the purge valve opens (higher rpm, drawing fumes into the engine), it seems the first thing it would do is draw fumes directly from the tank as the two ports are side by side. (There were filters over both those ports to prevent contamination, or anything being drawn into the engine by the vacuum. I removed the filters for the photos.) If the engine created enough vacuum, then it would start drawing air in from the vent hose in the reverse of the flow described above. Air would come up the long drain hose, down the small chamber, up the large chamber and into the purge port drawn by engine vacuum. Well and good. Except at the rate the tank generates vapor when hot, the second part of that equation may never happen. The purge vacuum may just draw vapor from the tank, maybe never even keeping up with the rate of generation, and certainly not cleansing the charcoal. So when you shut off, or the valve closes, you are defeated. The fumes pass thru the “full” charcoal and out the hose.

In my case, I am certain there was never any liquid sloshed into the canister. The charcoal was totally dry, the foam rubber totally dry with no signs of liquid anywhere. If liquid had been in that canister, I would have seen it. I had bad fumes right before the canister was removed but the canister was totally dry. In my case, I'm sure the volume of fumes just overwhelm the small canister and go out the bottom of the hose. Since the canister is warm on the 2011's and the hose is warm, the fumes do not condense inside but get pushed down the vent hose and when they hit the cold air at the bottom, they condense and cause the drips. On my 2011, the hose from the tank to the canister has a 90-degree fitting on the tank, then rises vertically at least three inches over about a foot or more of horizontal length before turning down to the canister. I personally believe that fuel would not slosh thru a 90-degree fitting and then go uphill all that distance through a small diameter hose. Now if the tank were overfilled and subject to thermal expansion, I could imagine fuel being forced into the hose but without accurate knowledge of the headspace built into the tank and the degree of expansion, I can't say if that is likely or not. In my case, I am sure that did not happen. Your situation and your opinion may be different.

Staying away from controversy, I hope this at least helps with understanding what's inside that mystical canister.

[jwulf74]

I see the problem... the vent is supposed to the ocean as labeled on the canister, not to the atmosphere. Stick the vent hose in the water and no more fumes.

All joking aside, thanks for the pics and write up. That gives me a lot better idea of how that is set up and supposed to work.

I wonder now about moving the canister closer to the front of the bike where the air box used to be. That would allow it to do its job but in a hopefully cooler spot. I also wonder what kind of pressure would build up in the system if the vent were modified to have a pressure relief valve on it that would only open at certain pressures...that would prevent anything from escaping and giving it a chance to cool but if the pressure reaches X then the valve would open and allow it to vent... any thoughts?

[Craniac]

Gypsy: Thanks for the pics. It is exactly what I needed.

Looks like there could be a valve of some sort on the port coming from the fuel tank.

My closest dealer is a 400 mile round trip. Not worth the wasted gas to have it "fixed" under warranty.

My plan now is to cut it in half near the bottom. I have enough power tools to make it easy. Next try to lengthen the canister to increase capacity. Refill with activated charcoal from the pet store. Then mount it where the '14s mount.

Doubt I will get to it today.

[Craniac]

Found this on the web. The foam at the bottom is a "volume compensator". This drawing also shows a bit of a tube inside to prevent the new vapors just being sucked into the engine. I'm guessing the foam is supposed to keep the charcoal tight against the top so the fumes have to travel a little way through charcoal. I might add a buffer tube to the purge outlet.

Also the roll over valve on top of the fuel tank is supposed to prevent liquid fuel from entering the evap system. I know that I get liquid fuel in the evap system. Have the pictures to prove it.

[Magdave]

The vent exit is the little hole behind the fill. No way can gas get pumped out it sits too high even if you filled to overflow IMHO.

[gypsy_100]

Gypsy: Thanks for the pics. It is exactly what I needed.

Looks like there could be a valve of some sort on the port coming from the fuel tank.

I was hoping for some high-tech valve or something but there is nothing there. Just a "dome" with the inlet port going thru it, then a flat area with a recessed square, and then an offset hole into the inside of the canister. The vapors come in thru the port, hit the flat square, go sideways to the hole into the canister. Why all the trouble, I have no idea. Possibly a liquid trap for a drop or two but that's about all it would hold.

Top Structure I.jpgTop Structure II.jpgtop half from inside a.jpgTop Filters b.jpg

Sorry photos aren't better but you get the idea.

[gypsy_100]

Found this on the web. The foam at the bottom is a "volume compensator". This drawing also shows a bit of a tube inside to prevent the new vapors just being sucked into the engine. I'm guessing the foam is supposed to keep the charcoal tight against the top so the fumes have to travel a little way through charcoal. I might add a buffer tube to the purge outlet.

Also the roll over valve on top of the fuel tank is supposed to prevent liquid fuel from entering the evap system. I know that I get liquid fuel in the evap system. Have the pictures to prove it.

Excellent drawing and very similar to what I found. The foam rubber was tight against the divider but maybe with the charcoal sitting on it, it does compress a little and is as you say, a "volume compensator". The generic drawing shows the inlet tube going a little ways into the charcoal to force the vapors thru at least some charcoal. Mine had no such tube. There was a little circular ridge that held the small foam filter in place (see previous post) but once the vapors got below that ridge, they could go straight over thru just a little bit of charcoal and then thru the white filter to the vacuum port or purge port. As for the "liquid fuel trap" in the generic drawing, I thought that might be the function of the "dome" and offset holes (see previous post again). But it would only hold a drop or two in the recessed square before it would fill up and begin dripping thru the hole into the charcoal. That could well be what it is, but at that point I gave up over-thinking it.

[Craniac]

Thank you for the pics.

I'm guessing it is the "liquid fuel trap" shown in the pic a few posts above.

While waiting for my son to help on a yard project, I decided I had time to remove the canister. There was no room for air to circulate around the canister. Engine heat would boil the vapors in the canister and release them through the overflow hose.

I believe there is room to reinstall it where the '14's have their canister. I do think BRP changes the design a little. the new one appears smaller in diameter from the pics so it should fit easier.

When I got it out, I didn't smell as bad as I expected. I may try simply remounting it away from a heat source and see if that helps. Not sure there is room to lengthen the canister. then I realized all I really need is more volume of charcoal. If it keeps smelling I will add a second homemade canister in the overflow line. All it needs is two hoses, one in, one out. Since gas vapors are heavier than air the in (from the other canister) should be lower than the out.

[gypsy_100]

Thank you for the pics.

I believe there is room to reinstall it where the '14's have their canister. I do think BRP changes the design a little. the new one appears smaller in diameter from the pics so it should fit easier.

then I realized all I really need is more volume of charcoal. If it keeps smelling I will add a second homemade canister in the overflow line. All it needs is two hoses, one in, one out. Since gas vapors are heavier than air the in (from the other canister) should be lower than the out.

According to the parts diagrams, the canisters are the same for all years including 2014 -- 709000090 for $66.99 (as Roger pointed out earlier). I, too, thought about increasing the volume of charcoal with a second container but then wondered how strong the vacuum is and would the vacuum be strong enough to pull the same volume of air back through more charcoal. Once again, I gave up overthinking it. For testing, you might have to bypass the purge valve to apply the vacuum to the canister(s) and compare the vacuum pull at the air inlet with one canister and with two. Just a thought.

[SNOOPY]

I'd like to say something here....


Gypsy, you freaking rock for the pics!!!




Okay, carry on....

.

[RBS66]

That would be awesome if BRP recalled 2013's to redo our canisters and install it where the 2014's are located. I have had terrible fumes and also drips on my driveway last summer.
Thanks Gypsy and Craniac I think I have a better understanding of how it works now. Messing with it on my own is definitely out of the question.

[Bob Denman]

Backyard "Mechanicking"; at it's finest!

[Craniac]

Just finished remounting the canister. Pics later.


Sent from my iPhone using Tapatalk

[Bob Denman]

[SNOOPY]

Just finished remounting the canister. Pics later.


Sent from my iPhone using Tapatalk

I am am really interested in what you find out. And if I should do the same!

[Craniac]

This is what the canister looked like when I finally got it out. It was just sitting loose, not in the mount.
evap move 003.jpgevap move 005.jpgevap move 004.jpgLOT

There is a LOT more room on the right side with it out. I went for a short ride and the right panel is quite a bit cooler than the left side. I think the added airflow will help cool the exhaust pipe and fuel tank.
evap move 001.jpg
You can see all the way to the bottom of the engine now.

I went to the Home Despot and bought a small bracket.
evap move 006.jpg
One of the holes closest to the bend had to be enlarged. I then sandwiched the bracket between the frame and the black plastic piece under the seat.

[Craniac]

evap move 007.jpg

This is the bolt I used pictured from above, the one next to the red handle. Remove the bolt, wiggle the bracket in until the enlarged hole lines up and put the bolt back in.
evap move 008.jpg

Then I used a large hose clamp that I already had from some old project and mounted the canister. The overflow is at the top. The purge vavle outlet is at the bottom. I figured the was best since the vapors are heavier than air.
evap move 009.jpg

Next I ran the purge hose from the canister along the right side of the tank and to the purge valve. I was careful to avoid sharp objects. My wife and kids are always telling me to avoid sharp objects.
evap move 011.jpg
After the pic I tucked the hose up a little.
evap move 012.jpg

[Craniac]

Next I removed enough plastic to get to the top of the tank. I replaced the factory hose with a new hose three feet long. I should have gone longer and wrapped the hose over the frame backbone. It attaches to the valve behind the filler. It is black with yellow stripe on mine.
evap move 014.jpg

I ran the hose to the inlet on the canister. I removed the factory overflow hose and hooked it to the canister.
evap move 018.jpg

I routed the outlet through the frame support and above the drive belt. I wanted to find a better location but this was the best I could do.
evap move 016.jpg I left the protective cover on the hose since it goes near sharp things. I guess I need a protective cover too.
evap move 017.jpg

Put all the tupperware back on and went for a short ride. Right side panel is noticeably cooler than the left. Too cool today to tell for certain but...NO gas smell right now!