Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

ZZR 250 Problems

Discussion in 'Technical and Troubleshooting Torque' started by bebo3, Jan 2, 2008.

  1. I recently changed the oil, spark plugs and battery on my bike, it worked for a few days and rode approx 30km with no issues.

    I noticed i had filled the oil over the half way mark, to more than full (while on centre stand).

    I took it out yesterday for a short ride , and experienced throttle problems, engine revved to about 7k then wouldnt go further. Then slowed the revs down for a turn, then it stalled.

    It would not start again even with the choke pulled fully in.
    It starts if i leave the bike sitting for an hr or so.
    I am not comfortable riding the bike to a mechanic fearing it would stall again.

    What could have caused this? Also, what problems could overfilling the oil cause?

  2. I am not sure about the stalling problem. It sounds to me like the carbies are being flooded and its starting after 1hr when they drain a bit. Others here will know more.

    Regarding the oil, how much over the full mark did you overfill? If its just a little bit I wouldn't worry too much. But if its quite a bit over the full mark you should drain some until it is within the correct range otherwise it may cause engine damage. Again others will be able to expand on this.
  3. edit: double post
  4. I'd warm up engine for a few minutes. Then let it sit for a minute, then check oil. If its more than the line, drain some out so that its only at the top of the line.

    Also, clean and reoil your air filter.

    After that, check that plug leads are on properly if it still running weird.
  5. Thanks for the help,

    I mucked around with the idling screw and it worked. It started fine for a while but now it doesnt work. I cant even start the bike, could i have made it worse by moving the idling screw too much?
    I let the bike also warm up previously and the oil is about half way once its warmed up.
  6. Yes, or too little. Same thing as giving it too many revvs whilst you're turning it on.

    Try playing with it, and playing with a bit of choke as well.
  7. Overfilling by to much will pressurise the crank case and can force excess oil into the combustion chamber and among other things foul plugs.
  8. Ok ive narrowed it down to a battery problem, the tacho jumps and makes a creak sound (not starting) when i hit the starter and i checked with a voltmetre and it says 10.84 volts for a NEW battery.

    I will try charge it or replace it hopefully that works, im really anxious T_T.
  9. Actually, excess fuel will cause the bike to run rich, as if the choke is on. The excess fuel won't readily drain away by itself. Whatever caused the excess fuel will continue to cause it.

    Instead, it is more likely a lack of fuel. Or, if the oil is dramatically overfull, such as by an extra litre or so, it possibly could cause plug fouling problems. You cannot check oil level while the engine is running...which was possibly implied in another post by the OP.


    Trevor G

  10. Sounds more like a lack of fuel than anything else. It was just dribbling in enough to fill the float bowls enough after a period. Or else there is a blockage in the fuel tap/filter, giving the same result.

    Or else you simply have let the fuel get too low. That's a common problem in here.. :)


    Trevor G

  11. Did you adjust the idle mixture screw or the idle speed screw? The mixture screw is small and will sit flush with the edge of the carb.

    The speed screw is usually quite large (to make it easier to adjust without tools).

    Most mixture screws sit at around 1.5 turns from fully (gently!) screwed in. The idle mixture screw does NOT affect the engine, performance or fuel economy. It only operates at idle, and maybe a minute fraction above.

    I hope you are not expecting to check the oil level while the engine is running. It must have been shut down for at least 10 minutes to allow the oil to drain back.


    Trevor G
  12. Also this may be an obvious thing, but you should be trying to start it with it on prime.
  13. You might have a battery problem now, from trying too long to start the bike. That does not sound like the cause (or symptom) of the original problem.

    All the best

    Trevor G
  14. Thanks heaps for more advice but still problems, i checked spark plugs and they are light grey/brownish colour, which seems fine.
    Tried starting on prime to no success.

    Yeh the battery was just dying from starting it too much, would leaving the bike to sit for a few days help anything?

    And finally can excess oil cause starting problems or more when its running? i.e could running on too much oil cause starting problems the next day?
    And it is full when it is been sitting for 10 minutes on centre stand, i couldnt have filled more than a couple of mL over.

    - I've filled 15L only about 100 km ago.
  15. Alright some developments, i tried again starting on prime and it works, i took it for a spin ( changing it to ON whilest riding) and it gains power, but then once on a hill it stalls. Then i must start again on Prime only.

    What does this mean?

    EDIT: I suspect a blockage in fuel tap most likely if it was to reduce fuel so much in so little kilometres.
    (recently filled 15L, the previous owner said he had filled premium i fill unleaded)
  16. You have a vacuum operated fuel tap. When the engine is running manifold vacuum is applied to a diaphragm in the fuel tap to open it. Thus, when the engine is switched off, no fuel should run through. The Prime position is used to supply fuel when the engine is off, or when you have run out of fuel.

    The most likely problem is that the diaphragm in the fuel tap has a minute hole. To test, find the vacuum line and remove it from the inlet manifold.

    The next part is potentially dangerous. Check that no fuel is running out of the line, then suck on it. Seal the end of the line against your tongue after you have created the most vacuum possible - the vacuum will stay (the line will stick to your tongue) if the diaphragm is OK. If the diaphragm has a hole the vacuum will fall away in a second or two.

    Depending on certain factors the loss of vacuum seal can also allow more air into the engine, which weakens the mixture. It could also allow neat fuel to run into the engine via the manifold vacuum line, and create a hydraulic lock (the engine won't turn over fully).

    The other, less likely cause is that the vacuum line itself is perished and losing the vacuum into the atmosphere. Look for cracks in the line.

    All the best

    Trevor G
  17. I'm not sure, but it strangely starts every time every day now. So taking this opportunity i took it to Kawasaki Parramatta to get it looked and he says the carbs need cleaning .

    But all i saw him do was make the idle speed go lower a bit so he could show that it cut out when idling, am I being had? He says $300 for carbs cleaning on a zzr250. Sounds a bit much. Full service was done about 4000km ago.

    To be honest i thought it was pretty dangerous leaving idle speed so low that it would cut out, as if i rode it home and let it idle in traffic lights it would have cut out, so i moved the idle screw back to 1300-1500 rpm and set off home.

    If i dont get it cleaned and nothing further eventuates would it be safe to ride another 3000km and do a complete service then?
  18. Mmmm.. Pretty bs. zzr carbs are very very very basic and simple. 20-30 minutes for taking fairings off and putting them on, then half to an hour for taking carbs out, cleaning, adjusting and putting back in.

    I wouldn't pay more than 200.. then again I'd probably just do it myself :p
  19. Hmm, you think most people can do it themselves on zzr? Or more specifically, what special tools do i need?
  20. Very basic tools to get it out, screw drivers, hex keys, etc.

    To clean it you can use some carb cleaner, or compressed air, or both.