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Can't Start GSF250V - Choke?

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by flyer517, May 28, 2011.

  1. Hi All

    I was hoping for some guidance. I am a new rider, new owner, and barely mechanically literate. Long time lurker and first time poster here.

    My bike has started fine until today. Today the starter kicks over well but it won't fire. On one occasion while it was turning over it backfired loudly.

    The only thing I can think of is that I seemed to have left the choke open since the last time I started it briefly 2 days ago.

    Not knowing how these things work, is it possible that having left the choke open for that long, fuel has drained in to the cylinders and the engine is now flooded?

    If so, will leaving it overnight with the choke now firmly closed fix the problem? Or am i completely off track here?

    Thanks in advance and feel free to point me in a completely different direction if necessary.


  2. All the choke does is close down the amount of air going into the carbies which in turn makes the mixture richer. A richer mixture helps starting while the engine is cold. With the engine not running the choke has no effect, so leaving it on overnight will have done nothing.

    More to the point, why do you ask? Was this just a wild guess or do you know you left the choke on?

    If you have left the choke on while running, you will have been running rich and it is possible that the rich mixture fouled the plugs. Or if you don't normally need much choke and have had it on then it may have flooded the engine with the same effect. Normally if this is the case you will smell fuel as you tunr the bike over.

    If flooded, turn off the choke and if you can on your bike, turn off the fuel (not all bikes can) hold the throttle wide open and turn it over a few times to see if it will fire. If it fires turn fuel back on.

    If a bike doesn't start NEVER just keep turning the starter over. Do it in short bursts with a rest period in between to give the starter windings a chance to cool down. If the starter begins to slow down, the battery is starting to flatten. Stop and give a break.

    If it still doesn't start at some point you will need to recharge the battery.

    For a motor to run it needs fuel, air and spark, if you can't get it started you need to start working out what is wrong by elininating what is working. If you know absolutely nothing about motors it will probably be best to either seek help from a friend who does or if the problem persists take it to a mechanic.
  3. Thanks for that info.

    To answer your question, I didn't ride it with the choke on but had left the choke open since I last started it (ie; it hasn't been ridden with the choke open as you queried). I guess from your description it shouldn't have anything to do with this problem. But I mentioned it as it is the only thing that was out of the ordinary and coincided with this problem.

    I have a twisted ankle so haven't been able to ride for a while. Every 2 days or so I have been turning it over for a few minutes. All good until yesterday when I tried and it cranked but never fired. Tried again this afternoon but again it didn't fire though it continues to turn over.

    I tried your suggestions of turning the fuel off, choke closed and cranking it with the throttle wide open but no joy. I gave it about half a dozen tries. I've pulled the fuses on the headlights as with this bike they come on as soon as the ignition is engaged and really tax the battery. In any case, it doesn't sound any closer to starting. Or are we talking a lot more than half a dozen tries if it was flooded?

    Thanks again.


  4. Some obvious things to check which have caught us all at one stage or another is:

    Is the Kill switch in the run position?
    Is there fuel in the tank?
  5. Thanks Chris. Yes the starter is turning over so the kill switch is OK and the gauge is indicating half a tank (I just added around a third of a tank recently).
  6. If my bike won't start straight away with no choke (normal in the mornings in this weather), I'll gradually introduce the choke (no throttle) while holding down the ignition button until it splutters to life. This prevents flooding the engine. Works for me (usually around 1/3 choke is needed), and is probably worth a try.

    As stated above, opening the throttle while turning over the engine will clear it if it's flooded.

    If this doesn't work, likely suspects are spark plugs or carburettor.
  7. On some bikes, the starter will turn over wwith the kill switch on, they just won't fire. My bike is not like this and I am embarrassed to say when I borrowed LizzM's once I spent a good 15 mins trying to start it before I realised the problem.

    Pull the plugs, earth them and turn over and see if you have spark. If you do then it's likely going to be a fuel issue.