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Honda CB250F Hornet - How many K's a tank?

Discussion in 'Technical and Troubleshooting Torque' started by Rolkus, Jul 30, 2011.

  1. Had a few problems on the way to work today - coming off the freeway, changed from 6th into 5th to slow down to the 80 speed limit (Camera mounted on exit sign) then the bike lost power, as if I had run out of petrol. The K's on the bike show 166.

    So I pushed the bike about 3km to the petrol station to fill up. I could hear the petrol inside the tank as I pushed it but the tank only took 9 liters of fuel. Then wouldn't start, due to battery but that's another problem.

    How many K's should I get out of a tank?

    I was under the impression the Hornet had a 16L tank, which should get me about 300 or so K's.

    @Brig believes it could be a vapor lock, which makes sen e, as this has happened twice before (started both times previously, after opening fuel tank).

    The bikes going in for a service on Wed, but still need to use it tonight, Monday and Tuesday (To and from work).
  2. It sounds like you may have a pinched or blocked breather/vent hose under the tank, having to open the tank is a dead giveaway, I owned one of these for my first bike but be buggered if I can remember how many k's I got out of it LOL.
  3. Hey mate,

    First off, leave the fuel tap on reserve at all times, the bike can only do about 130 or so im told (i have run mine on reserve tap since i bought it at recommendation of previous owner) before needing to go onto reserve, that's probably what happened, so its better to just leave it on reserve.

    As for all out range, the longest i have done is 280km of 110kph riding. Needed a big fillup after that, around 20$ (i was not smart enough to look at how many L's i had purchased though) you could probably get 300, but i chicken out before then lol.
  4. Where's the reserve switch? I know nothing about this bike other than it goes :p
  5. There will be a tap under the tank, and don't know your bike intimately but on most Jap bikes, turning the tap to the down position is normal, turning the tap to the up position is reserve and turning the tap between these two positions is prime.

    If the issue was fuel and presuming you hadn't got to reserve yet - if it is a 16 l tank and you put 9l in then you had 7l left which sounds way too much for reserve which is usually about 4l - then I would agree with Bamm-Bamm and it sounds like a fuel lock.

    Unconnected: Why would you leave the tap on reserve at all times? Unless there is something specific about these bikes it would seem to defeat the purpose of reserve.
    • Like Like x 1
  6. because its non reserve tank is very small, and only lets you use less then half of your fuel before you run out and are at the side of the road scratching your head / having to turn the tap over. Not sure why this is the case, someone at honda clearly thought that we needed a huge fuel reserve. Getting 166 km out of the tank before reserve sounds about right, maybe a little more, but again i dont actually know as i have left my fuel tank on reserve since i got it.

    Easier to just leave it on reserve and keep and eye on your odo and fill up every 250 or so clicks.
    Also: the tap is on the left hand side of the bike, its a metal tap thing that has 3 positions mounted near the top of the engine. shouldn't be too hard to find if you have a look for a while, kind of blends in a bit though.
    • Like Like x 1
  7. Based on what unconnected said, maybe you did run down to reserve????
  8. Found it Unconnected!

    Was set to N! Thanks mate!

    Thanks to you too BM!
  9. Normal tank 150-170 ks.
    Not sure about the limits of the reserve tank, but I fill up by 200.

    On the Hornet, the tap facing right on on, down is off, left is reserve.
  10. I'd still use the 'Reserve' if I were you, then you'd get the message you need fule soon rather then accidently resetting odo or something like that and you might get stuck pushing a bike, I did mine today on a flat surface for a about 50 meters, 3 kms? fark that for a joke!!
  11. What message do I get that I'm on Reserve?
  12. The sudden 'I aint going anymore' like you got today, then you flick to reserve, keep going, reset your odo and check how far you go [first time round, say at 50kms] then fill up and see how much fuel you need to top up, reset your tap to 'normal' and you guesstimate your total milage.
    • Like Like x 1
  13. If you mean how do you know you are using reserve rather than normal, simply by the way your tank petcock is switched.

    If you mean how do you know when to switch to reserve, when you run out of petrol on normal. Ultimately the bike will stop and the trick is to do it when you start to run out. On a multi cycinder bike, one cylinder is likely to stop before the other(s). Generally a two cylinder will suddenly start running on one cylinder and it's pretty noticable - loss of power and lots of vibration. On a four when one cylinder cuts it isn't quite as noticable. On my four it's more a sudden lack of power rather than running rough, once I would have sworn it was a flat tryre rather than engine vibration. And my four seems to like to do it a stop lights so that it goes simply from running to not running.

    But with experience you will learn about how many k's you get from your tank to reserve and you will srtart paying more attention as you get up to that k's, assuming you don't just fill up again before that.

    Personally I wouldn't run a bike on reserve because if anything happens to reduce your normal milage (e.g headwinds, greater pay load or simply riding harder than usual) then if you run out , then you have run out, and you start pushing.

    If you leave run on normal and only switch to reserve when you need it then if you run out you will still have some reserve. However if you do this you do need to ensure that if you have switched to reserve, you switch back off it when you fill up.

    Whichever you should know how far you get on a tank and ensure you fill before you get too close to the end.

    Finally if you don't normally use reserve, you should for say 50-100 k's or so after a fill up just to ensure the reserve tubes are clear of crap.

    Sidenote: Reserve is usually a feature on bikes with carbies. Injected bikes don't usually have a reserve and have either a fuel gague or low fuel warning light system.
  14. Ah GreyBM, sorry I misunderstood, I was under the impression that there was some dead sign to tell me to switch over to reserve, other than the obvious 'stop going' method!

    Thanks again, got it all sorted.

    The switch on the Hornet is in an awkward position. On the ZZR250 it was convenient and could do it while riding, this one is a bit hard to get too.
  15. just practice getting to it while in a straight line. mine's in a pretty awkward position too, as in hard to learn how to find it by touch. but one day the bike ran out of puff, and I just switched it to reserve without pulling over and kept going.
    if I can do it anyone can do it (y)
  16. +1 to practice. If you can catch them when they start to splutter before they stop it's easier. Sometimes once they stop they can decide to be difficult restarting.
  17. Fuel tank is on reserve dies at 166km again. Can hear fuel in the tank.
  18. Got it working - rocked it back and forth a bit and it started... Why would I need to do that?

    And should it die if im on reserve already?
  19. If you are already on reseve I guess it could be your reserve straw is blocked and it's not picking up fuel.

    Are you sure you have it on reserve? What happens if you switch back to normal?