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Featured Care to help an aspiring rider get his zxr going?

Discussion in 'Technical and Troubleshooting Torque' started by Husker, May 7, 2015.

  1. Hi all.
    Long story short I've inherited a zxr250 from my dad, only problem is that its been sitting outside unprotected for the better part of a decade.
    Amazingly the thing cranks, I cleaned the carbs and its getting fuel, it has a spark and compression but the dam thing still won't start.
    So I need the help of someone on the mornington peninsula who is willing to let me borrow their cdi box so I can rule that out.
    If anyone is willing to do this for menor offer any helpful ideas I'd be eternally grateful. Email me if your avalable.

  2. Hello, nice to meet you.
  3. I assume your using new fuel?
    Try using a tin of 'start ya bastard' to spray down the air intake.
  4. Check the kill switch - corroded to a closed condition, or just in the "off" position.

    Compression test - if it spins a little "too easy" you may have valves stuck open. Open the valve cover first - look for any signs of rust within. Confirm that the valves open and close as they should when the engine is cranked, though as you said, it has compression - that is a sign which probably rules this out.

    New plugs - old ones can short out where carbon on the insulator ( on the inside) is thick and gets damp)

    CDI - generally when they fail, the engine will just be dead - no spark.

    Easy things to test/try.
    • Agree Agree x 1
  5. If it's got compression and a spark it should go. New fuel and some Start Ya Bastard, combined with a big, fresh battery should do the trick. If you can just get a couple of pots firing, the others should chime in.

    One thing worth checking (and not necessarily immediately obvious) is that mud wasps or some similar critter haven't built their nests in the exhausts and plugged them.
  6. #6 Husker, May 8, 2015
    Last edited: May 8, 2015
    Thanks guys but unfortunately I've done everything that's been suggested. I sprayed start ya bastard into the carbs and straight in. The plugs are brand new and so is the battery and yes its charged. The fuels fresh and under the rocker cover it all looks pretty clean . oh and there's a decent amount of air coming out the exhaust so I don't think it's blocked will check though.
  7. Are you using full choke no throttle? Choke cable perhaps? I had one and if u didn't use full choke when cold it wouldn't fire
  8. Yea chokes working fine (well the mechanism at least). Tried choke on/off, throttle full open/closed.
  9. #9 oldcorollas, May 8, 2015
    Last edited: May 8, 2015
    firing order correct?
    spark on every plug?

    if you have fuel,spark, timing, and air.. don't need much else :)

    can you smell fuel in the air coming out the exhaust?
    • Agree Agree x 1
  10. Are you getting any ignition or sign of the fuel being ignited such as smoke which could indicate flooding?
    The next step would be to double check the carbs are ok, to what level did you clean them?
    If the tanks been taken off, double check the vacuum and fuels lines are still attached and not pinched.
  11. Yea spark on all plugs and plugs are hooked up in correct order. Unless its electrical? (cdi box)

    Yea the plugs are wet and petrols getting to the cylinders i.e you can smell it, fully pulled the carbs apart cleaned it all (needles and such) with carb cleaner and besides even if it was the carbs it should still fire with strait start ya bastard right? or at least splutter.
  12. where are you holding throttle while trying to start?

    if it has any spark at all, something should be popping :)
  13. I've tried doing different thing with the throttle i.e full open,half open,closed,randomly twisting in frustration.
    What do you mean by "popping"? like a explosion/combustion "pop" because I get them but very infrequently and never replicable.
  14. that kind of pop. if revs slightly increase at a pop, then timing and firing order probably ok.

    I'd suggest just cracking throttle a bit.. or increasing the throttle opening by the idle setting screw.
    easy to get too much air and prevent start. I might be totally wrong though :D
  15. With my old one using any throttle was a no no if u wanted it to fire. Always full choke, zero throttle
  16. Na guys still no go. Gonna get a cdi box this week there's just no other logical thing it could be.
  17. Good news I got it running, was a combination of a new cdi box and a second more thorough cleaning of the carbies. I reckon Just a few weeks and I'll be joining all of you guys. Thanks for your help.
    • Like Like x 3