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Bike not starting, fuel/battery/plugs ok but no spark?

Discussion in 'Technical and Troubleshooting Torque' started by MeltingDOg, Aug 3, 2012.

  1. Hi all,

    Am wondering if someone could give me a few tips. After absolutely no problems for the time I've had it, went to ride the bike to work today only to find it wouldn't start. Engine turned over fine and fuel lines seem fine. Spark plugs are clean - it just wouldnt catch.

    I got a mate to push start me and it caught for a few moments then died again. After that no luck at all.

    Could this be a distributor or timing issue? If so does anyone know a good guide to fix/set them?

    It was pretty cold this morning, but Ive ridden it literally everyday this winter without any issues.

    Its a 2000 Honda VTR 250 - a pretty robust bike untill now.

    Any advice is appreciated! Cheers
  2. Kill switch accidentally activated?
    Scratch that, just saw "...it caught for a few moments then died again."
    Remove one spark plug, reconnect the plug lead and earth the body to th engine casing, spin the motor over.
    can you see/hear a nice fat blue spark?
  3. Did the engine ACTUALLY fire up when pushed, or just a 'burble' sound?? Check the kill switch [just incase]
  4. Yeah I did but as soon as I let the throttle drop a bit it cut out...

    I read somewhere that 98 Octane fuel might be coating the plugs. Ive been running 98 for the last few months. Has anyone heard of this before?
  5. Weird that it ran fine one day, then not at all the next. You'd think plug fouling would gradually get worse over days, IE. hard starting, rough running, increasing over a period of days.
  6. Have you done this yet?

    See above remove a plug and check its colour.
  7. Thanks for the advice all.

    Managed to get her running again by charging the battery. Whilst I had it idling I noticed a few things:

    - it would miss if I jerked the throttle to quickly. This would happen until it was well and truly warmed up.
    - There was a strange dull 'thumping' sound occuring occasional
    -It run real rough until properly warm.

    Now I might just be noticing it more now but I swear cold starting wasnt this bad earlier. This leads me to think theres an issue with the timing...
  8. So that bike has carbies?
    Sounds like the idle circuit is partially blocked or has water in it or similar.
    Open throttle quickly from idle and it stumbles usually means idle mixture too lean, or accelerator pump not working correctly. Couple this with not running well until thoroughly warm and I'd say the idle system in the carbies is messed up somehow.
    Find the adjustment specs for the air bleed (idle screws) and set them to the correct settings before you spend more time and money chasing the problem though. Also check carb sync setup and make sure they're at least close to correct.
  9. Hi Guys,

    Re the VTR 250 Carby side of things. you will discover that when you go looking for the air fuel mixture screw on each carb it is in fact a specialised genuine honda tamper proof adjusting screw E.G. a tiny purtruding bronze shaft with a flat face on one side of it. Only the with honda service tool can you adjust the fuel air mixture.

    Regardless this is not at all likely the prob !

    E.G. Below assumes you have a fully charged battery & you charging system is tested & working correctly,

    1, Like mentioned before ensure there is a consistant spark via each cylinder by removing both plugs inserting them in the suppressor caps & shorting the plug electrode the the head or barrel of the engine whilst cranking (Check both) 1 at a time.

    Inconsistant spark at 1 cyl but not the other is either a faulty sp plug /plug cap/ or ignition coil (there are 2 coils 1 for ea cyl )

    Irratic spark to both cylenders ( CDI ) unit or more accurately formally termed (TCI) module failure or the onset of failure.

    Their is no adjustment for the ignition timing on a VTR 250 & it is not necessary as the timing is fully electronic.

    2, If there is good consistant spark to both cyl then very likely the carbies need stripping down & professionally overhauling (this is a professional job) & best attempted only via a skilled mechanic. Cleaning out your fuel tank & tank filter beforehand would save the mech some labour.

    I hope the above factual advise helps,

    Cheers netriderchchick
  10. start with the cheap easy and simple stuff. then go to the less likely moderately expensive stuff, then go for the new bike.
    Check your airfilter as well, It may be contributing to the problem.