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Engine cutting out

Discussion in 'Technical and Troubleshooting Torque' started by Smeagol, Oct 25, 2009.

  1. I am a new rider (6 months) and bought a 2006 Hyosung Comet 250 to get me through the 12 month restrictioin period, a great bike for what it is and up until now its been trouble free. I bought this as it was at the right price and low kilometers.

    I now have an intermittent problem, its happened half a dozen times in the last month. The issue is that the engine totally cuts out when I am on the Freeway and doing 100 kph, it literally dies, engine stops as though I have hit the kill switch, all lights are still working etc... this is scary in itself, and luckily I've been able to pull over safely. Once pulled over and bike is in neutral, it will start and run for a day or two maybe a week. I work in Essendon and ride to and from the Eastern Suburbs every day as this is my only mode of transport.

    My thinking is if it were electrical, surely it woul'nt resart so easily, so I'm thinking its fuel related, there is always plenty of fuel in the tank, I changed the fuel filter yesterday, and hope that is the end of it, but cannot be certain.

    Has any one ever had a similar experience, maybe on a different bike or does anyone have any other ideas, could it be the electric fuel pump, or the carbies (twin carbies) if one was blocked the other would still deliver fuel, even if it ran like a dog.

    I await your reply. Thanks
  2. it could be an intermittent fault in the kill switch/ignition(Unlikely)
    Could be fuel although I would think it unlikely as you can start it straight away.

    My money on the other hand(And knowing that it does happen) would be the Kick Stand Switch. I would either disconnect(<-If you can remember to pull the clutch in like you should be when you start it) it or replace it. As I would put odds on it being the problem here. IIRC they are like $20 could be more or less.
  3. Are you sure you want to ask why?????:D:D:D:eek::eek::eek::bolt::bolt:
  4. I think if it were fuel, it would cough and splutter, before coming to a halt. I heard that there was a recall about 2005 re the CDI unit being programmed to cut out at 6000 revs, but my bike is 2006 and that should have been fixed from new. Im leaning toward one of the cut out switches, as you suggested, Side stand, neutral or clutch or even the ignition switch, will have to wait to the weekend.

  5. Another possibility is that the vent in your fuel cap is blocked. This will stop the engine getting enough fuel, particularly at higher speeds. When you pull over the pressure gradually equalises and then it starts again. Next time it happens, open the fuel cap as soon as you've pulled over and see if there's a vacuum in the tank, you should hear the air getting sucked in if there is.
    It certainly sounds like you're not getting enough fuel through, you could also check all fuel lines for blockages.
  6. Yea ^^^ I was gonna suggest the tank vent as well, but as posted above if its an instant power loss not a splutter then that's probably not the case. Have you been opening the tank after it stalls? If its the blocked vent tube then opening it will obviously relieve the vacuum and let the fuel flow fixing the problem. But if it has been restarting without you opening it, or potentially releasing a vacuumed tank then that's probably not the problem. I'd be paying Hyosong a visit if you can't sort it tho because a problem like that can obviously turn very dangerous!
  7. Thanx for the tank vent theory, I will try this the next time it happens, I suspect that is not the case but all avenues must be tested. I am suspecting its a trip to the dealership at $140.00 per hour, I hope they have foolproof test equipment as these problems never show when they are under the microscope.

    Thaks for suggestions.
  8. Disable your kickstand switch, or replace it. That is where the problem will most likely be.
  9. Side stand switch is now disabled, its now a matter of time to see if the cutting out dosnt happen, I will give it a week and if all is good, fit a new switch. Thanx for you help