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CBR250R - Problem Starting!!! Please Help a Newb!

Discussion in 'Bling and Appearance' started by X-Bob, Feb 6, 2006.

  1. Hey,

    I've just about gone nuts trying to solve this problem... pretty much on the verge of giving up and calling a mechanic. Thought I might throw it open to everyone and see if ive missed something.

    I recently bought a CBR250R(K)
    Originally it took a while to warm up and being new to non EFI engines i used the throttle as well as the choke to start it. This wasn't a problem right away but everytime I went to start it it would get progessivly harder to start. So... more choke and more throttle. (Stupid I know)

    The last time I rode it... after I realised I should stop using throttle while the choke is on, it was still difficult to start but got going and I rode it for about 30 minutes.

    Since then it hasn't strted at all.

    After doing some reading I came to the conclusion ithat i've either:

    1) foiled the plugs
    2) flooded the carburetor
    3) flattened the battery and was charging it with the wrong charger
    4) or... bought a crap bike

    I've replaced the plugs and checked that they spark
    Used a multimeter on the battery. Shows 14v.
    removed the air filter - which has a little effect when i fully open the throttle (I can hear some actual firing)
    And come to the following conclusion

    I've flooded the carburetor
    There's a battery problem still.

    This is the bit that's confusing me:

    I've checked the battery so it seems like it's most probably the carbs. BUT the manual says if your spark plugs are wet (which the new ones now are) its an ignition problem ie not getting spark (but i am).

    So... is it possible to get too weak a spark. (My charger works at 4amps and the battery is recommended for 0.6A - 3A max) But still have correct voltage?

    Or does this sound like the carbs?

    Or... should I just replace the fuel... Ive heard of people that have had problems starting they're bikes and replacing the fuel has worked. Seems weird though cause the fuel was alright last time I rode it.

    Would appreciate any advice anyone can offer.

  2. I have actually run out of fuel in the garage, and the bike has failed to start the next time I've tried to ride it. :oops:
    Try reserve, and/or check for fuel in tank.
  3. Got full fuel tank.

    Wet plugs means I have fuel but am missing either spark or air.
    Have spark cause i've seen it.
    So either the spark is too weak or im having air problems or mixture problems.

    If you flood the carb can they drain themselves?
    If you flood the carbs will it effect the fuel/air mix?
    Is it possible to have too weak a spark?
    Pretty sure it's not an air problem as the air filter looked new.
  4. Sounds to me like you've flooded it.

    This is what I would do:

    - Hook the bike up to jumpers from a car (you'll need all the battery capacity and more), leave the car running
    - Use full choke on the bike, NO throttle while turning it over until it starts to fire. Some will say use wide open throttle (can be quicker), but just plain leave the throttle alone to avoid confucing things
    - It will take a while to fire, usually starting on only 1 cylinder first, gradually firing on all 4. This can take some minutes of it turning over (hence jumped off a car) depending on how badly flooded it was. Just be patient.

    - If this fails, do the above with all of the plugs taken out (severely flooded!). Clean the plugs (or better, replace them [yeah I know they're new!])

    - If none of this will get it to start (highly unlikely) then perhaps it will be an ignition problem. Test the reg/rec to see that it's putting out the correct voltage. Like I said highly unlikely, these bikes are pretty reliable.

    They're easily flooded with too much throttle, especially when cold. Just because the plugs are wet doesn't mean that you have an ignition problem, what it means is that it's so flooded that combustion can't take place!

    Hope this helps, keep at it (common newby problem!) and let us know how you get on.
  5. I have just had the same problem, the bike was turning over and the fuel was flowing. My C.D.I unit was blowing. But the cause of this was the crank sensor, 1 was pick up was only working intermittently and in turn spiked the C.D.I when the motor was cranked. I changed the pick ups and have not had a problem yet. My friend that helped me told me he has seen this a few times in the past. So maybe have this looked at and see how you go, let me know how you go.

  6. Just tried your advice cammo...

    Don't have a car around at the moment to jump off but i do have a battery charger so i'm taking the VERY long route but...

    So far 1 dead battery.
    It's on charge now, so ill try again in a few hours.

    Thanks everyone that has posted so far.
  7. Oh yeah, and what's a CDI?

    Sorry if its a noobish question.
  8. Not going to be the battery, if it's cranking ok then it should run. If you're getting good spark, then the ignition system *should* also be fine. It does sound flooded.

    How I'd start it:
    With a fully charged battery and the bike sitting still for 20 minutes (evaporation), hold the throttle full open, keep the choke off, then crank it while keeping the throttle wide open. Hopefully it will kick. If it doesn't, then look at the electrical system.

  9. This won't be the prob on xbob's bike because he's getting spark.

    Charging the battery is the very long route! Seriously, I wouldn't bother unless you have a car to jump the bike off.
    In my experience, if it's that badly flooded it will run the battery out SEVERAL times before it starts to fire cleanly. Jumping it off a car will also probably make it turn over faster, quickening up the whole process. Not being silly, it's just not worth wasting your time without a car, you'll just keep running the battery out. Not good further down the track if the battery's not in peak condition!

    BTW- The 4A charger will be fine, just don't charge it for as long as you would!
  10. CDI = Capacitor discharge ignition.

  11. This does seem to work for most bikes, but the 4 cylinder 250's I've had just don't seem to like that method. They're fussy about fuelling at the best of times, especially below 5k rpm! It will simply take a *little* longer with no throttle, and reduces the risk of more flooding when newb's don't think it's working so try twisting the throttle on and off a bit more.
  12. I never use the choke on mine even on the coldest morinings, just use a tiny bit of throttle and hit the starter with your thumb and it starts first time everytime.

    Good luck with getting it going again
  13. Couldnt you take the plugs out and leave it for a bit, the un burnt fuel would evap out, or you could burn it out with a light?

    Thats what we use to do to go karts when they got flooded.

    I'd already tried hitting the starter with throttle open but didn't realise it took so long to do.

    5 battery charges later... WOOT!!!

    Thanks Cammo and everyone else who posted!