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Project Bought a ZXR250C.

Discussion in 'Your 250cc Projects' started by Linkin, Jan 30, 2017.

  1. Andych

    Andych Well-Known Member

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    It certainly sounds nice and crisp. It’s amazing the difference it makes with some nicely honed bores, reconditioned ( mostly) head and a carby overhaul makes.
    And it was probably cheaper than jacking up the number plates and swapping something else in.

    We won’t mention the “other” cylinder head though


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  2. Linkin

    Linkin The Apprentice Premium Member Dirty Wheel Club Contributing Member

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    I've yet to take some photos of just how gnarly it truly is. I posted on the valves a little while back. About the only thing its good for now is to stick on the grinding wheel to see what material it is - there's a thread that @Frankster has, and his mechanic reckoned they were titanium. I do not think so, but the sparks from the grinder will tell for sure.

    Lapping titanium / coated valves is generally considered bad practice, but I think the ZXR's pre-date titanium valves by a fair bit... they are using cast iron liners and not nikasil plated alloy bores, as well.
     
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  3. Andych

    Andych Well-Known Member

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    That is a bonus that they are plain cast iron liners. Nikasil coated alloy makes them expensive to rebore and impossible to just hone.


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  4. ShaneP

    ShaneP Well-Known Member Premium Member Contributing Member

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    If your idle isn't turning down, check the clamps aren't stopping the throttle adjusters between the carbs. Or a synchronising mechanism ajar?
     
  5. Linkin

    Linkin The Apprentice Premium Member Dirty Wheel Club Contributing Member

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    The clamps are secured in their spots on the manifolds, they are indexed. The throttle is closing fully to the stop, the high idle will be the balance being out I bet.
     
  6. ShaneP

    ShaneP Well-Known Member Premium Member Contributing Member

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    Are all butterflies closing? Otherwise, check The choke circuit closes, no missing or leaking vacuum hoses or missing air jets?
     
  7. TonyZXR

    TonyZXR Active Member Premium Member

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    Valves are probably stainless steel . Doubt they would be sodium filled but you never know
     
  8. Linkin

    Linkin The Apprentice Premium Member Dirty Wheel Club Contributing Member

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    Yep the valves are stainless, definitely not titanium
     
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  9. Frankster

    Frankster See the World before you leave it Staff Member Premium Member Ride and Events Crew

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    So, what has been added to the exhaust valves to stop them being magnetic?
     
  10. Frankster

    Frankster See the World before you leave it Staff Member Premium Member Ride and Events Crew

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    What are you talking about? Who told you ZXR bores were Nikasil plated? If they were, you wouldn't be able to bore them and use oversize pistons.
     
  11. Murdo

    Murdo The Good Doctor Staff Member Premium Member Ride and Events Crew Contributing Member

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  12. Andych

    Andych Well-Known Member

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    If the valves are Stainless Steel then they wont be magnetic depending of course on the type of Stainless Steel.... Plus I think @Linkin said the bores were not Nikasil Plated.. or maybe I am going nuts.. (highly probable :))
     
  13. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

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  14. Frankster

    Frankster See the World before you leave it Staff Member Premium Member Ride and Events Crew

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    So the inlet valves are martensitic steel and the exhaust are austenitic steel. Thanks @Murdo
     
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  15. Linkin

    Linkin The Apprentice Premium Member Dirty Wheel Club Contributing Member

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    The ZXR valve stems are also two different diameters on the upper and lower portions, I believe they two different parts that are welded together
     
  16. Linkin

    Linkin The Apprentice Premium Member Dirty Wheel Club Contributing Member

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    AAAARGH! Pinkslip fail because using the horn sometimes causes the engine to stall :headbang:

    Anyone want a ZXR? :commando:
     
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  17. ShaneP

    ShaneP Well-Known Member Premium Member Contributing Member

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    At least yours runs the rest of the time!
    But that is bizarre. It's like some used the kill switch to power the horn.
     
  18. Linkin

    Linkin The Apprentice Premium Member Dirty Wheel Club Contributing Member

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    Found a more "friendly" pink slip place down the road :thumb_ups:
     
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  19. Andych

    Andych Well-Known Member

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    I hope the first one didn’t fill out the paperwork with the rejection.
    If they did they will pick you up when you do the rego as they log it online and it shows up that you were knocked back and then went elsewhere.


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  20. Linkin

    Linkin The Apprentice Premium Member Dirty Wheel Club Contributing Member

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    No they just checked it and told me it'd fail.

    Of course, by the time I finished work today, all the RMS centres had already shut up shop, thank god for online renewal
     
    Last edited: Oct 20, 2018 at 3:57 PM

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