Project Grasshoppers FZR 3LN3

Discussion in 'Your 250cc Projects' started by GreyImport, Feb 16, 2014.

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  1. Grasshopper

    Grasshopper Well-Known Member Dirty Wheel Club

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    Yep, will do.... stay tuned! (pardon the pun!)
     
    Grasshopper, Mar 8, 2015
    #241
  2. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

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    I heard u today from my lounge room ..... that thing is really howling now. :D
     
    GreyImport, Mar 8, 2015
    #242
  3. Grasshopper

    Grasshopper Well-Known Member Dirty Wheel Club

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    How did you know it was me??? LOL.....:neo:
     
    Grasshopper, Mar 8, 2015
    #243
  4. Willrcr15

    Willrcr15 Well-Known Member

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    Where did you get the parts from?
    I've gone as far as I can with mine & she's petering out at idle now.
    Time to try new parts, sounds like you've had great success.
    I went as lean as possible, looks like too lean, but reading what you've been through is like what I've got.
     
    Willrcr15, Mar 8, 2015
    #244
  5. Linkin

    Linkin The Mechanic Premium Member Contributing Member Dirty Wheel Club

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    You need 2 kits for the outer carbs, and 2 kits for the inner carbs. The kits are $50 each

    NOTE THESE ARE FOR 3LN3

    http://www.motorcyclespareswarehouse.com.au/products/k-1203yks-ky-carb-repair-and-parts-kit

    http://www.motorcyclespareswarehous...oducts/k-1203yku-ky-carb-repair-and-parts-kit

    Below are for 3LN1

    http://www.motorcyclespareswarehouse.com.au/products/k-1205yks-ky-carb-repair-and-parts-kit

    http://www.motorcyclespareswarehouse.com.au/products/k-1205yku-ky-carb-repair-and-parts-kit

    You really only need the needles and emulsion tubes... good luck sourcing them though. At least with these you will have brand new parts for anything else that is broken or worn.

    Set your pilot screws to 2.5 turns out as well
     
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    Linkin, Mar 8, 2015
    #245
  6. Grasshopper

    Grasshopper Well-Known Member Dirty Wheel Club

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    Ok, an update... Have set the needles to 3rd Pos down (centre position)... I can tell its running a little richer, and the power delivery is better... the bike just launches itself in first and second gear; so much so that the front forks bounce up and down as I lunge forward and change gears - so I will need stiffer springs there.... Next step is to do a fine tune with the pilot screws after I do a longer run (they're still 2.5 turns out)... Happy Days! I now feel that I'm operating at optimum power now.... fine tuning will just be the icing on the cake... @maelstrom
     
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    Grasshopper, Mar 8, 2015
    #246
  7. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

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    Thankyou and goodnite :dance2:
     
    GreyImport, Mar 8, 2015
    #247
  8. Grasshopper

    Grasshopper Well-Known Member Dirty Wheel Club

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    Yeah, thank you and good night to me... :dance2:
     
    Grasshopper, Mar 8, 2015
    #248
  9. Grasshopper

    Grasshopper Well-Known Member Dirty Wheel Club

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    Just an update: I tuned the bike, it's not hard... easiest way to do it is to chock the tank up and get in from there, you don't burn your hand that way, and it's real easy..... I got the desired result: tune each one, and when the idle goes up, stop there and reset the main idle... they all responded well, except the last one (cyl 1 I think), it didn't seem to make much difference, but in the end I kind of found the middle ground with it.... might try that one again later... But - the bike flies - smooth across all revs, torque down low, and screams when high - it's AWESOME... Grey, you need to ride it... I'm very happy..
     
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    Grasshopper, Mar 11, 2015
    #249
  10. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

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    Hooray! Finally someone tunes by ear instead of "turns out".
    Well done Grasshopper.
     
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    maelstrom, Mar 11, 2015
    #250
  11. Phil

    Phil Senior Member Contributing Member

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    Well done Grasshopper, I'm 100% behind Blair on this one.:D 90o screw driver=winner
    My mechanic Jason always does this and results are always brilliant.:thumb_ups:
    Now, get out of "Dodge" and hit the open road, you and your bike deserve this.:cool:
     
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    Last edited: Mar 12, 2015
    Phil, Mar 12, 2015
    #251
  12. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

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    .. they all responded well, except the last one (cyl 1 I think), it didn't seem to make much difference,

    You probably know this, @Grasshopper, but as compression goes down vagueness goes up. Have you set the valve clearances?
    What is the response on the other 3 cylinders in comparison eg, 1/4 turn each way and the rpm starts to drop?
     
    maelstrom, Mar 12, 2015
    #252
  13. Grasshopper

    Grasshopper Well-Known Member Dirty Wheel Club

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    Yep, good point. The other 3 cylinders respond fairly well... That's the next job I think, valve clearances to be checked...
     
    Grasshopper, Mar 12, 2015
    #253
  14. Joker

    Joker See "about me" for contact details. Contributing Member

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    Can you educate me oh wise one...

    1. Did you turn pilot screws all the way in before starting to turn them out? Or start from where they were and keep turning out?
    2. What do you mean by "reset the main idle"?
     
    Joker, Mar 12, 2015
    #254
  15. Linkin

    Linkin The Mechanic Premium Member Contributing Member Dirty Wheel Club

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    1. He started with them 2.5 turns out and then adjusted the first 3. The last one didn't seem to make much of a difference

    2. After adjusting one carb until the idle rised, he then used the idle screw to turn it back down. Rinse and repeat for the other carbs. Carb #4 didn't make much of a difference when adjusting the pilot screw.
     
    Linkin, Mar 12, 2015
    #255
  16. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

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    Main Idle knob is probably a less confusing term ....

    carb idle.jpg
     
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    GreyImport, Mar 12, 2015
    #256
  17. kiffsta

    kiffsta Senior Member

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    kiffsta, Mar 12, 2015
    #257
  18. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

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    @Stu
    You do not think about turns out from bottomed. You are finding the point of highest idle.
    1/ Wind the screw SLOWLY in until you hear the rpm start to drop as it becomes too lean. This is the first point.
    2/ Now keeping track of how many turns, wind the screw SLOWLY out. the engine will pick up and then start to slow again as it becomes too rich. This is the second point.
    3/ Now split the difference. In other words set the screw halfway between those two point. That is the optimum.
    4/ Your idle should now be too high. Adjust that big knob that Mr Grey spoke of and repeat this process as many times as you need and with all 4 cylinders.
     
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    maelstrom, Mar 12, 2015
    #258
  19. Joker

    Joker See "about me" for contact details. Contributing Member

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    Ah sweet I get it now. When I read it at first I thought it was just turning the screw out until the revs increased and once you hit that do something with the main idle.

    So we're finding the halfway point on each carb at idle between "max lean" and "max rich" (suggesting going any leaner or any richer is over doing it past these points), then dropping the RPM back down to comfortable levels when we find that point.

    I should get onto that too!
     
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    Joker, Mar 12, 2015
    #259
  20. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

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    Yes, that is kind of it. Each time you lower the idle back to where it should be you can rinse and repeat but it will be come more sensitive.

    For example let's imagine the first time that you did it 1/2 turn each way and the rpm would start to drop. Then you set it in the middle. It is idling too high now because you have set the mixture correctly, so you lower the idle to where it should be. Now if you repeat the process you might find that only 1/4 turn each way and it falters. Put it in the middle and that is where you want to be.
    Now start on the next cylinder. You get better at it with practice.

    After setting like this I have found that when the engine is warm you can just touch the start button and it will spring to life. No throttle, no hassle.
     
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    maelstrom, Mar 12, 2015
    #260
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