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Help FZR250 jet kits

Discussion in 'Yamaha 250cc In-Line 4's' started by Dropdead53, Oct 17, 2018.

  1. Dropdead53

    Dropdead53 Active Member

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    Hey guys,
    Just wondering if anyone here has ever bought a carby jet kit from “6sigma” off eBay for an fzr250?
    Was the kit any good?
    And what mods did you have?
    I want to run pod filters and a free flowing muffler on my fzr and thinking of getting this 6sigma jet kit off eBay and want to know if anyone has fitted one before?
    Or is there another brand worth looking at?
    Cheers.
     
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  2. my67xr

    my67xr Bike Enthusiast Staff Member Premium Member Contributing Member

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    Welcome to the forum,
    Just get the Keyster full rebuild kit's from Motorcycle Spare's Warehouse, they're around $50 per carb.
    You'll need 4 kit's, 2 outer kit's and 2 inner kit's.
    https://www.motorcyclespareswarehouse.com.au/search?q=fzr250
    Make sure your bike has the correct carby's for the model, eg 3LN1, 3LN3 etc
    https://www.2fiftycc.com/index.php?threads/identifying-your-fzr250-3ln-bodywork-frame-engine-carburetors.3469/


    The needle's and emulsion tube's will most likely be worn and i'm not sure if you get new emulsion tube's in the Sigma kit.
    And i'm not sure if you would need 4x of those Sigma kit's either $376 + post

    There are Keyster tuning kit's available too, but you don't get all the extra part's that are in the rebuild kit's
    https://www.webike.ng/ps/#!p.b=1941&p.m=13908&p.c=1180&p.sk=1

    I wouldn't worry about the pod filter's unless you have a lot of money to try and get the carby's to work right on a dyno.
    Just get a new air filter and run the standard air box.
     
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    Last edited: Oct 17, 2018
  3. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

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    The Sigma thing is complete rubbish. You get a drill bit, to drill your slide that you can do yourself anyway, some pieces of paper with nonsense written on them and some main and pilot jets that you can buy anywhere. They don't have any real dyno charts. It is a complete farce, but hey they are no doubt make a lot of money with their scam. They even started a new one with nitrous kits, a cream bulb dispenser and a piece of hose.
    Pod filters will be a nightmare with CV carbs. Read this https://litetek.co/docs/InSearchOfFreeLunch.pdf
     
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  4. Murdo

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

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    If you want to waste money/time and loose horsepower, then by all means go ahead.
    If you want a bike than runs sweet, revs clean and is reliable then stick with stock. Pod filters are a joke that nobody has realised is funny.
     
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  5. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

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    :welcome:

    Half the postings on this forum are on getting carbs and a bike to run right .... and the hardest of all are the FZR ..... even if u want to change stuff u should always get it running correct with the stock setup initially

    The FZR250 goes like a scalded cat in its stock factory setup including the muffler, if its running 100% ..... its not called the 'screamer' for nothing

    As mentioned above u need Keyster kits to change the emulsion tubes/needles and a Litetek kit to renew all the seals and o rings

    https://litetek.co/ReplacementPartsYamaha.html

    And theres mountains of info on here about overhauling, cleaning, rebuilding and setting up and tuning these carbs.

    Ive ridden an FZR250 for years and guess what ... my carbs are on the bench in pieces ... again ... because its not running right ... again :commando: :D
     
  6. Dropdead53

    Dropdead53 Active Member

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    Thanks for the reply guys, You have made it easier to make the decision to buy the keyster kits. I guess I was just curious if anyone had tried the alternative jet kits as opposed to the Keyster kits.

    Do the Easter kits come with the emulsion tubes??

    And is there a ‘how to’ on doing the carb slide mod with the drill bit? And what’s the benefit?
     
  7. my67xr

    my67xr Bike Enthusiast Staff Member Premium Member Contributing Member

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    The slide drilling mod is easy to do, just a matter of drilling the 2x hole's in the bottom of the slide with the appropriate drill bit
    It let's the slide move quicker giving it better throttle response.



    The Keyster kit's come with the emulsion tubes

    This is one of the 3LN3 kit's
    1 keyster.jpg

    Included in this kit:

    Chamber Gaskets (2)
    Needle Valve
    Jet Needle
    "E" Clip
    Screw Air
    Spring Air
    Noozle
    Main Jet #100
    Main Jet #42.5
    Slow Jet #10
    Jet, Air Bleed #112.5
    "O" Ring (7)
    Washer
    Screw Throttle
    Spring Throttle
    Other (3)




    Note: FZR250 Serial Numbers

    3LN1: MARCH 1989- 3LN-218101-279000
    3LN3: FEB 1990- 3LN-279101-325000
    3LN5: MAY 1991- 3LN-325101-340000


    Also when you buy the kit's double check the jet's are the correct one's for the carb's, the Keyster kit's i bought had the 2x outer carb's main jet's (1&4) in the inner carb kit's so i had to swap them around)
    https://www.2fiftycc.com/index.php?threads/fzr250r-3ln3-bdst28-carburetors.9643/#post-105292


    Here's a link to the Litetek Viton seal kit's for the 3LN3/3LN5 carby's too if you are going the full rebuild (remember to check you have 3LN3 carby's)
    https://litetek.co/Carb_Kit_Yamaha_FZR250_3LN3.html

    Have a read through my FZR thread there's a bit of info there regarding tuning etc, click on the blue FZR250R 3LN3 link at the bottom of this thread
     
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    Last edited: Oct 18, 2018
  8. Swaler

    Swaler Active Member

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    Where do folks find the rubber diaphragm slides for the FZR250 3LN1 carbs?
     
  9. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

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    I forgot now, but I am pretty sure you can use Suzuki ones. The GJ73 uses BDST carbs.
     
  10. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

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