Honda CBR 250 Forum banner

1 - 20 of 25 Posts

·
Registered
Joined
·
378 Posts
Discussion Starter #1
Before any smart asses make jokes, yes the gas goes away from riding it...lol ;)
Here is my issue. I fill my tank from a gas can... don't ask why... I just do. What is happening is I fill to the top, enough gas to cover the plate in the gas tank.... then when i'm done i watch it and it slowly drops about 1/2" down then stops. So i add some more gas.... it drops again then stops. did this a few more times.... keeps doing it. Where the heck is it going?:confused: No leaks, no puddles, it's just vanishing. same 1/2" drop every time.
 

·
Registered
Joined
·
681 Posts
You must have gotten the magic gas tank model.
 

·
Registered
Joined
·
378 Posts
Discussion Starter #5
where are your overflow hoses coming out to? are they in your lower fairing?
the only hoses i see are the crank case breather and a black one. neither are dripping tho.
 

·
Registered
Joined
·
378 Posts
Discussion Starter #7
Think i'm gonna call Honda and see what they say.
 

·
Registered
Joined
·
378 Posts
Discussion Starter #10
when i fill mine up at the pump...it sits there at the same level and doesnt drop any
how high do u fill? I was putting enough in to totally cover the triangle bar and the round plate.
 

·
Registered
Joined
·
256 Posts
Ok this thread seems pretty silly, but I have experienced this to some degree. First of all I am sure there is some reason for the silly design but I am not pleased that tiny gas particles fly all over the tank when I fill up. I think the gas shows over the metal plate due to all of the air bubbles the turbulence from the bar creates. It settles. Then another squeez of the nozzle and again air bubbles and turbulence, then settles, etc. Just a thought?
 

·
Registered
Joined
·
193 Posts
First motorcycle, huh?

The tank has baffles inside to help prevent sloshing and guide noobs on how to fill the tank. As the gas near the top of the tank while fueling, the air that was caught between the baffles is displaced by the gas. The air escapes slowly, so you need to keep adding small amounts. You may notice small bubbles appearing at the surface as the air escapes. Eventually you will reach a point were all the air has been displaced and the tank contains only gas. Of course, at this point the tank is so full that fuel may run out of the overfill tube. I haven't had this happen to me yet, but it would happen all the time with my old VT750DC Shadow Spirit. That tank didn't have the top plate so filling it to the brim was a much quicker and easier task.

My current fill up procedure is to take it up to the top plate and then add 10 to 12 small shots from the nozzle until the level stays above the top plate but is still a half inch or so below the bottom edge of the rim. This usually gives me a full 6 bars on the gauge for 20 miles or so before it drops to 5 bars.


 

·
Registered
Joined
·
706 Posts
Do these things also have Evap? On cars with evaporative emissions, when someone clicks the pump a few extra times the fuel goes into the evap canister and causes a CEL and occasionally other problems. I thought I'd seen that they do have it somewhere.
 

·
Registered
Joined
·
378 Posts
Discussion Starter #15
Ok this thread seems pretty silly, but I have experienced this to some degree. First of all I am sure there is some reason for the silly design but I am not pleased that tiny gas particles fly all over the tank when I fill up. I think the gas shows over the metal plate due to all of the air bubbles the turbulence from the bar creates. It settles. Then another squeez of the nozzle and again air bubbles and turbulence, then settles, etc. Just a thought?
I fill from a can and pour very smoothly so I doubt it's air bubbles.
 

·
Registered
Joined
·
16 Posts
Since the fuel tank holds 3.4 gals of fuel, you could always let it run out of gas and then try putting in a measured 3.4 gals and see if the fuel level is up to the rim of the gas cap like I would expect. If the gas isn't leaking somewhere then I would think this would let you know nothing is wrong and gas is simply filling in hoses or areas of the tank slower than you are putting in the fuel.

Just a non-motorcycle expert's though.

Thanks
Rudipides250
 

·
Registered
Joined
·
378 Posts
Discussion Starter #17
I decided not to fret it. My shop Helm Manual will be here prob by friday so i'll just look at the dissection to see if there are any overflow hoses, baffles, ect.
 

·
Registered
Joined
·
1,377 Posts
Since the fuel tank holds 3.4 gals of fuel, you could always let it run out of gas and then try putting in a measured 3.4 gals and see if the fuel level is up to the rim of the gas cap like I would expect. If the gas isn't leaking somewhere then I would think this would let you know nothing is wrong and gas is simply filling in hoses or areas of the tank slower than you are putting in the fuel.

Just a non-motorcycle expert's though.

Thanks
Rudipides250
Good to see good old fashioned common sense from a non-expert.

There are plenty of experts on this forum on topics as diverse as clunks, rattles, how to fill 'er up, gear and technology to save us from our own stupidity, how to break in a horse, and how to encounter steering.

It all gets confusing to an old chappy, so I just have to grab my boogie board, ride off to the beach and surf a few waves to clear the old noggin. Then a beer and a game of pool on the way home makes my day.
 
1 - 20 of 25 Posts
Top