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New, old, git in town & starting issue

Discussion in 'Yamaha 250cc In-Line 4's' started by old bike git, Nov 27, 2012.

  1. old bike git

    old bike git New Member

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    Hi all,
    New member to the forum from the UK with a 37,000 kms 1990 3LN.
    Really impressed with the bike having recently ridden it back to back low milaege Honda CBR250/4.
    Even given the differences in the mileage I have to say the Honda is probably higher build quality but it's emphatically a little sterile for my liking.
    Very functional, almost clinical and 100% Honda. Honed and polished but somehow lacking a little je ne sais quoi.
    The FZR by comparison is just a little more feral and sparky like it has an attitude?
    One thing I can report on is the undoubted benefit of that EXUP valve. Crack open the throttle outside the power band on either machine
    and just feel the difference. The Honda just bogs and although it doesn't die it fails to make satisfactory progress.
    The Yamaha just seems to dig deep and then inexorably just pick up the pace.
    Handling wise I couldn't make a call as my FZR shock linkage has started to seize but that's fixed now <!-- s:D --><img src="{SMILIES_PATH}/icon_biggrin.gif" alt=":D" title="Very Happy" /><!-- s:D -->

    One question I'd like to ask is about starting. I have a good battery and there doesn't appear to be a cranking issue.
    The bike is reluctant to start from cold and will only catch if the choke is left off. When it does catch it's a 2 then 3 and finally four pot chime in.
    Also find it seems to stall with no load if I pull up from a run and don't blip the throttle before coming to a halt. Various people have suggested
    the bike is running rich due to worn float valves and/or perished rubbers in the carbs.........Any thoughts folks?
    Not had any signs of fuel out the overflows yet but exhaust and plugs are generally on the black side of good. Bike has a new air filter BTW.

    Any suggestions welcome and thanks.
    Old Bike Git
     
    old bike git, Nov 27, 2012
    #1
  2. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

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    North by NW NSW Oztralia - Tamworth
    My Bike:
    *Kawasaki ZXR250C *Yamaha FZR250R 3LN1 *Yamaha FZR400 *Triumph Bonneville 750 T140V *Triumph Daytona 675 *Triumph Tiger 800XC
    Old git ea?......how did I know u were from the UK before I even read your post? <!-- s:lol: --><img src="{SMILIES_PATH}/icon_lol.gif" alt=":lol:" title="Laughing" /><!-- s:lol: -->
    Welcome to the Feral Fizzer Forum from another old bastard (as we say in Australia <!-- s:alcoholic: --><img src="{SMILIES_PATH}/icon_all_coholic.gif" alt=":alcoholic:" title="Alcoholic" /><!-- s:alcoholic: --> )

    You will find things a little quiet around here these days but if youre patient a few of the long term "experts" drop in at times.

    Im still learning the FZRs but I would be looking at the carbs...theres a load of info here about them and a carb sync on these bikes is essential.
    Splits in the rubber boots is a common problem also.

    Also have a look at the EXUP to see if its working correctly (as it affects low revs)......

    http://www.cartestsoftware.com/fz1/exupmaintenance.html

    Parts list and diagrams......
    http://www.yamaha-motor.com.mx/Manual_Partes/Catalogos/Deportivas/FZR250/3LN6_1993.pdf

    <!-- s:thumbsup: --><img src="{SMILIES_PATH}/th_thumbs_up.gif" alt=":thumbsup:" title="thumbs up" /><!-- s:thumbsup: -->
     
    GreyImport, Nov 27, 2012
    #2
  3. old bike git

    old bike git New Member

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    Cheers mate.
    Will be leaving the bike alone until it actually stops raining here.
    7C and almost a monsoon so not conducive to spannering outside
    and my new workshop is a long way off being finished <!-- s:( --><img src="{SMILIES_PATH}/icon_sad.gif" alt=":(" title="Sad" /><!-- s:( -->
    Thanks,
    O-B-G
     
    old bike git, Nov 27, 2012
    #3
  4. dontz125

    dontz125 Active Member

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    Hi, OBG - welcome to the madness!

    Hard starting with individual cylinders chiming in as the engine warms is a classic sign of tight valves, for which the entire FZR line is infamous. Download the 400 manual and read up on the process of checking and adjusting valve shims, then download the 250 manual (Japanese only) and the spec sheet (English, but no instructions) for the numbers. It's not uncommon for the intakes to have less than 1 thou cold clearance - spec is (IIRC) 6-8 thou!

    Your difficulties once running say to me that your carbs are in dire need of a good clean and sync. As ever as always on bikes this age, check your carb boots, air filter, plugs, caps, and wires. It's also probably past due for an oil change and filter, rad flush, brake fluid change (lots of people forget /! neglect this one). Man - time to get working on mine!
     
    dontz125, Nov 28, 2012
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  5. old bike git

    old bike git New Member

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    Thanks Dontz,
    Lot of wisdom condensed in that post sir!
    Have already been through the valave clearances and they were fine.
    Oil and coolant all swapped out along with a new air filter...........didn't like the lock wire and silicone sealer holding the old one together.
    From this and your comments I reckon its carbi time!!!!! <!-- s:-? --><img src="{SMILIES_PATH}/icon_Eyecrazy.gif" alt=":-?" title="Eye Crazy" /><!-- s:-? -->
    Just need to get my workshop finished and some power laid on before I get stuck in.

    Oh some heat would be good as well. It was -2C this morning and I am not freezing my butt off outside anymore working on bikes; far too old now for such stupidity.

    Cheers,
    OBG
     
    old bike git, Nov 30, 2012
    #5
  6. Viper

    Viper New Member

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    its not stupidty its dedication <!-- s:biker4: --><img src="{SMILIES_PATH}/th_Biker_4.gif" alt=":biker4:" title="Biker 4" /><!-- s:biker4: -->
     
    Viper, Dec 1, 2012
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  7. blueyedjackel

    blueyedjackel New Member

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    lol AMEN brotha <!-- s:ditto: --><img src="{SMILIES_PATH}/th_Ditto.gif" alt=":ditto:" title="ditto" /><!-- s:ditto: -->
     
    blueyedjackel, Dec 2, 2012
    #7

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