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Gas Cap Vent Alignment


hiro
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Bike smells like fuel in the garage. It might be OK, but it raised a question about venting. The first photo is not my bike, but is shows the vent connection between the cap and tank. I'm wondering if it's possible that my vent is misaligned a little, partially blocking the vent. I wonder if that could lead to pressure being release too slow and continuing after I park in the garage. Sometimes I hear either vacuum or pressure being released when the cap is opened.

142930765.DqxQnRZm.jpg.da1aa315ac1845676224be9f2309b683.jpg


The second photo is my bike. Is it normal for the nipple thing to hit the edge of the seal? I wonder if it slips into place or remains pressed into the seal. (The cap closes in the SW direction.)

gas_vent_close-up.jpg.5319ff49a9b32ff536a373fc7c7f511e.jpg

 

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36 minutes ago, Isaac's Papa said:

So gross. 

 

Side question: Are mods able to block individual members and their threads? No reason... just asking. 

No, I had 2 peeps on block before I became a mod. Soon as I got mod status I was subjected to their drivel again.

If it makes you feel better, they can't block us either.

Edited by Tonik
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@hiro The hole you have identified is not the tank vent.  Most tanks on modern bikes are sealed to at least a bit above atmospheric pressure to meet EPA evap/emission standards and the tank vent goes directly to an activated carbon canister, usually hidden under the seat in the tail section.  Fuel vapors from the tank are trapped in the canister and then drawn back thru the motor by manifold vacuum while the engine is running.  The hole you show in your pics is actually just a drain for rain/wash water or spilled gas during refueling which dumps thru a hose thru the frame under the bike.  Doesn't explain why you're smelling gas.

Edited by Bubba
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1 minute ago, Bubba said:

@hiro The hole you have identified is not the tank vent.  Most tanks on modern bikes are sealed to at least a bit above atmospheric pressure to meet EPA evap/emission standards and the tank vent goes directly to an activated carbon canister, usually hidden under the seat in the tail section.  Fuel vapors from the tank are trapped in the canister and then drawn back thru the motor by manifold vacuum while the engine is running.  The hole you show in your pics is actually just a drain for rain/wash water or spilled fuel during refueling which dumps thru a hose thru the frame under the bike.

No it's not. Its a Kaw. Its a negative pressure vent. It sucks air in when the tank cools so it doesn't implode the tank. My Voyager has the same set up. So did my Nomad. The Nomad made this really cool whining noise when it let air in. Happened shortly after you shut it down.

I would tell all the Harley tards it was my turbo winding down.

It also not the source of his gas smell.

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Yeah, there is another hose from drainage. The one shown vents from the tank through the gas cap, then it seems to run to the ground. I don't think this model has a evap system.

The Ninja 300 has the whine when shut down. This Ninja 650 does not whine, for better or worse.

BTW, I've seen mods in which the vent holes are made larger to get rid of the whine.

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On the Nomad you could pop the seal out and take a bit of the spring out and it would vent faster and get rid if the whine. I never did it, prefered to troll the Harley tards at gas stops.

If you decide to take it apart tape the tank opening up so you dont drop the seal, ball and spring into the tank.

But I dont think anything is broke here.

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16 minutes ago, Isaac's Papa said:

Yeah.... I don't feel any better. 

You could always ignore my posts unless someone complains? You think I feel any better getting useless replies? I don't exactly have a team of mechanics to set up and maintain my bike. heh Maybe I'd be better off in a Kawasaki forum anyway. At least they would know what I'm talking about.

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2 hours ago, motocat12 said:

no but dirt can get in and clog,kinked hose down in the works... blow it with compressed air or a straw to see if it flows through.

Do the water drain hose too.

Tried that and it seems OK. Not sure about venting through the cat itself. I can only guess that it's OK.

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20 minutes ago, Tonik said:

But I dont think anything is broke here.

I would hope it isn't something like this old recall. Found it on a Vulcan forum.

Recall Date:09/09/2008

HTSA Recall #: 08V473
Kawasaki Recall #: MC08-15

Risk: On the affected fuel tanks, under certain riding conditions, fuel can leak from between the tank filler neck and the fuel cap gasket. Fuel leakage in the presence of spark or flame could cause a fire or explosion possibly resulting in injury or death.

At least death is the worse thing that could happen in that case. heh

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2 hours ago, hiro said:

You could always ignore my posts unless someone complains? You think I feel any better getting useless replies? I don't exactly have a team of mechanics to set up and maintain my bike. heh Maybe I'd be better off in a Kawasaki forum anyway. At least they would know what I'm talking about.

Just busting nuts hiro, any real trouble you get I guarantee some one from here will step up to help you. This is just classic OR where they just vent, some burn, mostly volatile scenario but at the end it's all just gas. 

 

On a side note , my zx6r used to whine too IIRC

Edited by NinjaDoc
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2 hours ago, Tonik said:

No it's not. Its a Kaw. Its a negative pressure vent. It sucks air in when the tank cools so it doesn't implode the tank. My Voyager has the same set up. So did my Nomad. The Nomad made this really cool whining noise when it let air in. Happened shortly after you shut it down.

I would tell all the Harley tards it was my turbo winding down.

It also not the source of his gas smell.

 

2 hours ago, hiro said:

Yeah, there is another hose from drainage. The one shown vents from the tank through the gas cap, then it seems to run to the ground. I don't think this model has a evap system.

I stand corrected.  Mea culpa...

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Pic links don't work for me so I don't know what you're trying to show. The whine whistle or whatever you want to call it is not negative pressure.  It is positive pressure and is being caused by the gas vaporizing creating pressure. A valve holds that pressure  at a certain level. When it exceeds that limit it vents causing whistle whistle whine whine smell smell. What you hear when you open the cap is pressure release not vacuum. If it was vacuum you would have to somewhat force the cap open. Why does this happen when you park? Thanks for asking. Think about it. As you are riding the all the heat from the engine is getting blown straight back and also is going around the tank cooling it as well. When you stop the heat from that hot lump of metal goes straight up trying to percolate the gas in the tank creating excessive pressure that is released. Hence the smell. All the above is null in void if you have an actual fuel leak. Two things that can help a little. One park it outside while you stow your gear a and let it cool down. Two is to fill your tank at the closest gas station before you go home. Till next time. Class over. I gotta go to work. 

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8 hours ago, Al Z. Heimer said:

Pic links don't work for me so I don't know what you're trying to show. The whine whistle or whatever you want to call it is not negative pressure.  It is positive pressure and is being caused by the gas vaporizing creating pressure. A valve holds that pressure  at a certain level. When it exceeds that limit it vents causing whistle whistle whine whine smell smell. What you hear when you open the cap is pressure release not vacuum. If it was vacuum you would have to somewhat force the cap open. Why does this happen when you park? Thanks for asking. Think about it. As you are riding the all the heat from the engine is getting blown straight back and also is going around the tank cooling it as well. When you stop the heat from that hot lump of metal goes straight up trying to percolate the gas in the tank creating excessive pressure that is released. Hence the smell. All the above is null in void if you have an actual fuel leak. Two things that can help a little. One park it outside while you stow your gear a and let it cool down. Two is to fill your tank at the closest gas station before you go home. Till next time. Class over. I gotta go to work. 

That's probably it. The 650 heats up more than the 300 and the fairings probably hold in some heat while sitting still. The cap opens easy, so that's good. It takes a little more pressure to close it compared to my other bike (for sale!) No loss of power as far as I know, and no tank implosion or explosion yet. heh No drips on the ground. I checked for kinked hoses. Well...at least I learned about the ventilation system.

3559d1151454508-fuel-tank-caved-again-de

Edited by hiro
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On 5/1/2017 at 7:04 PM, Tonik said:

No it's not. Its a Kaw. Its a negative pressure vent. It sucks air in when the tank cools so it doesn't implode the tank. My Voyager has the same set up. So did my Nomad. The Nomad made this really cool whining noise when it let air in. Happened shortly after you shut it down.

I would tell all the Harley tards it was my turbo winding down.

Mine does that too, I just always say she's squealing from hitting her G spot on the last set of twisties. I'll just turn and say "your welcome"

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