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Project First bike, the FZR250 3LN

Discussion in 'Your 250cc Projects' started by I_b_pirate, Feb 17, 2020.

  1. ruckusman

    ruckusman White Mans Magic Master Premium Member Dirty Wheel Club

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    Cockroaches end up in the darndest places - I found them all through the spark plug cover and actually down into the plug recesses on Dads ute when I changed the plugs

    I don't know which one would have originally thought that was a good place to hang out, but they obviously lead the others to disaster
     
  2. I_b_pirate

    I_b_pirate Well-Known Member

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    Fixed up the carbs so now it’s getting fuel and not flooding but still not sparking, thinking ignition timing is out as it keeps “popping” out the intake. Is there a way to retard the ignition a bit without needing a timing light?


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  3. ruckusman

    ruckusman White Mans Magic Master Premium Member Dirty Wheel Club

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    Timing is fixed and there's no mechanical adjustment available or necessary - plug leads to correct plugs - it's wasted spark, so leads go from one coil to plugs 1 & 4, leads from the other coil go to 2 & 3

    don't worry others, including myself have gotten the plug leads messed up at some stage
     
  4. I_b_pirate

    I_b_pirate Well-Known Member

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    Ah haha yeah my uncle plugged it all up before I picked it up, pretty sure he put 1&2 on the same coil


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  5. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

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  6. I_b_pirate

    I_b_pirate Well-Known Member

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    So leads are fixed to the coils and are numbered so they are fine but I have a feeling he’s mixed up the plugs, one has a grey and the other is orange, both have a red cable. And which is neg/pos?


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  7. Linkin

    Linkin The Mechanic Premium Member Contributing Member Dirty Wheel Club

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    Coils earth through the spark plug, the small spade connecters should be power to coils from TCI and tacho signal but I'm not certain on that
     
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  8. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

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  9. I_b_pirate

    I_b_pirate Well-Known Member

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    I think it's getting too much fuel? How do I turn it down? I tried to post a video but it won't let me.
     
  10. ruckusman

    ruckusman White Mans Magic Master Premium Member Dirty Wheel Club

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    OK - simple question time, don't be offended because sometimes the obvious gets overlooked

    How many KM's on the clock, this will give us a small clue as to how much wear is likely on the needles and emulsion tubes

    You've mentioned spark leads now going to correct plugs 1&4 and 2&3 from their respective coils, now given that the wiring has been tampered with, two possibilities, the first one shouldn't have an effect as the TCI charges the coil primary, then collapses it to ground to create the spike in the secondary to cause the spark...

    So the individual wires to the respective coils could be backwards, although I cannot see it having an effect

    BUT given that the coils are on colour coded plugs - IF the spade connectors were removed from the coils themselves and re-connected incorrectly - then the spark will be going to the incorrect plugs, just try swapping those two colour coded plugs to the coils

    BTW - tight valve clearances will cause difficult starting also
     
  11. I_b_pirate

    I_b_pirate Well-Known Member

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    It says it's done 13908 but I dunno. Suppose it hasn't been on the road for like 10 years.
    I did find a lot of gunk in the brother on the carbs so I'm wondering if I should strip them down completely to clean them properly but just a bit nervous with all the springs (never done carbs before).

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  12. ruckusman

    ruckusman White Mans Magic Master Premium Member Dirty Wheel Club

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    Your pics of the carbs show them to have been relatively clean, do get the litetek kits from @maelstrom, but there's no need to strip them down twice.

    In the meantime it should run and with that few KM's the needles and emulsion tubes should be OK - I got mine with approx 34K kms and there was wear on the tubes which caused more problems especially as the km's went up, yours should run fine as it is

    If you have either a JIS screwdriver or a posidrive screwdriver, which I think you obviously already have, don't use phillips, you'll make a mess of the screws, take the tops off of the carbs, you'll find a lot of disintegrated black foam, that comes from inside of the filters connected to the large diaphragm breathers at the top, joined between the pairs, so there's two of them

    the filters do open from memory - been a long time since I had them apart

    If you want to do a clean in the interim, remove the uppers and diaphragms then soak the whole lot in petrol - just be aware that the needles for the centre pair -v- outer pair are either different or shimmed to a different height so they need to go back into their correct carbs - getting those wrong will affect how it runs when ridden, but not failing to start at this point

    I'll find the post about the needles and include the link in a bit
     
  13. I_b_pirate

    I_b_pirate Well-Known Member

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    There does seem to be some wear on the needles and one of the screws is seized on so I'll have to get the vice grips onto it. This was the carbs that was getting a lot of fuel too. 99c10928344ff8ee3f0953cff6fd78bd.jpg

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  14. ruckusman

    ruckusman White Mans Magic Master Premium Member Dirty Wheel Club

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    The best way to check that needle would be with a razor blade along the straight section then hold it up to the light and if you see a crack if light through a gap then expect the emulsion tubes to be kaput also, but it should still try and come to life

    Here's how to check float levels - and fuel levels, these have a specified fuel level of 9.2mm above that casting line - that's the one to check

    You can check that easily, with the carbs on the bike, just need some clear tube, small clear fuel line if you have it, otherwise the clear PVC in about 3-4mm I.D. from memory will do it, just needs to go over the float bowl drain hole

    https://2fiftycc.com/index.php?threads/my-fizzer.872/page-32#post-15537

    Here's a thread with lots of links

    https://www.2fiftycc.com/index.php?threads/new-member-sydney-australia.8839/#post-90802
     
  15. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

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  16. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

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    and you have some that Santa sent but I guess you are over carbs, carbs, carbs and carbs for the moment. :)
     
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  17. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

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    You know I cant remember if I put those in the last time I pulled the FZR carbs or I just kept the Keyster crap and put in my best original needles .... I guess Ive been too engulfed in EFI via laptop lately :lolsign:

    I need a real workshop to get back into the real stuff!
     
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  18. Andych

    Andych Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    Or get a Postie Bike.... only 1 carby on them :dance2:
     
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  19. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

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    postie.jpg
     
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  20. I_b_pirate

    I_b_pirate Well-Known Member

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    So I'm sure it's the carbs cause I just tried to start it again and now it's not getting enough fuel so I put a bit of fuel down the bastards and she almost fired up. But I can't afford the kits right now as I'll need the needles and tubes as well as all the seals so I'm contemplating starting the tear down and clean up everything else till I get the kits.

    What are the thoughts? Tear the lot down and paint the frame and do brakes/ suspension/ electrical until I get the kits for the carbs? Or focus on the carbs and get it to fire properly then tear it down?

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