NEED HELP !!!, SHA 14mm Carb giving me issues!

Discussion in 'Intake & Exhaust' started by Mojo, May 11, 2012.

  1. Mojo

    Mojo New Member

    Joined:
    Dec 26, 2011
    Messages:
    60
    Likes Received:
    0
    Hi there, i am back once again, i ordered a offset intake manifold and an SHA 14mm Carb from CustomMotoredBicyles.com and i ran it,

    http://custommotoredbicycles.com/yahoo_site_admin/assets/images/IMG_5157.8105234_std.jpg

    Started Great, Throttle Response was awesome, the auto choke worked great All though my motors have Never once needed a choke to start or run from first start (don't ask why) infact,

    on Most the carbs i have used i took the choke off.. as it only got in the way of the stack and air filter i run with, Until now that is,

    i have ran this new carb with slight issues for the past 20 miles or so, the issues have become worse,

    if i give more than 70% throttle i began too four stroke and i gain no speed even though i am giving more throttle, i am topping at 32 mph, with the NT stock with a good air filter i get 42 mph, ALSO ''not the focus of this post but needs mentioning'',

    No matter how i adjust my idle screw on ANY carb i have ranging from, CNS, CNS v2, NT, Speed carb, and now my SHA 14mm dell clone, i CANNOT get this engine too idle,

    closest i come is taking away gas flow 100% at idle and VERY Lightly revving the throttle just too give it enough to stay running, the issue i face here is she rev's off the freaking chats when i do this SO EASY then takes for ever too slow down,

    IF i let go of the clutch ''and i have'' she acts like a bad ass dirt bike and goes running away with a wheele lol , so i tend too never idle and as i slow to about 6mph i press the kill switch and hit the clutch so she kills out,

    i would not assume this is healthy for the engine.

    my issues : at 70% throttle and past i began four stroking around 32 mph, and after 20 or so miles today, i start the bike and go for a run i hit a jump at about 20 mph and land, shortly after landing the engine dies out, so i tried to start her up-

    she wont start, so i engage the choke, and she starts right up, i give her WOT to release choke shortly after she started,

    as soon as i release the choke she dies again, i have tried running it to warm her then releasing , tried at 10 mph, then at 30 mph,

    No matter when or how i release the choke she dies out, BUT if i release it and it dies, at enough speed i can once again engage the choke while slowing to a stop and she will start back up right after choke is re-engaged.

    at first it ran like my other carbs, no choke needed too start or run, i use this rig as a dirt bike so it takes beating from time to time, but i do maintain this bike DAILY as its my fun bike and i know she takes beating :).

    So far what i have tried and looked at too fix this is :

    i have Checked fuel tank and lines for bits of stuff blocking gas flow and such, i have checked spark plug, its gaped at 0.30 and a golden brown like a well baked chocolate chip cookie, so not lean or rich (Running 32:1), Took off the air filter and cleaned it out with Gas and an air compressor to spray out all the bits that may or may not be in there,

    Finally i let my pride go and ''asked for directions'' cause right now i am lost this motor is acting very strange, and unhealthy Yet it has great compression, 500 miles, new carb, new expansion chamber exhaust, good oil ratio,

    everything checks out so i am not sure what is going on!




    zpt
     
  2. Mojo

    Mojo New Member

    Joined:
    Dec 26, 2011
    Messages:
    60
    Likes Received:
    0
    ~solved~

    I took the Carb and dismantled her, the float bowl was clean, everything seemed perfect, so i took and blew '' by moth and boy it tasted bad :D '' through the tiny little JET this SHA 14mm has, and it seems air was flowing though it flawlessly,

    So i figured wth lets hit it with the air compressor just too be sure, after witch i staired for a moment then decided too test again my mouth for a feel of air flow difference, WHAT a change~!~

    so some thing had got the jet all plugged up i did NOT see what it was, but assume dirt...

    ANY ONE THAT BUY'S AN SHA 14MM CARB FROM CUSTOMMOTOREDBICYLES.COM BE SURE TOO STUFF SOME FOAM STOCK TYPE FILTER INSIDE THE CNS STYLE FILTER THAT COMES WITH THESE AS THE ''CAP'' OF THE AIR FILTER AND THE ''METAL MESH'' DO NOT MEET UP AND LEAVE VERY LARGE GAPS WITCH ALLOW CRAP TOO GET SUCKED IN, HAPPEN TO ME ON MY FIRST 20 MILES OR LESS OF USE!
    brnot
     
    #2 Mojo, May 11, 2012
    Last edited by a moderator: May 11, 2012
  3. action170

    action170 New Member

    Joined:
    Aug 25, 2013
    Messages:
    1
    Likes Received:
    0
    its a simple carb and very east to use, your problems stem from a simple main jet issue, the main jet will affect the idle and top end performance since the main jet is the only one that can be replaced and will alter the air jetting and idle jetting settings, i live at 2500 feet altitude and run a 65 main jet, my carb came stock with a 68 main jet and i encountered some 4 stroking and rich plug environment, i also run motul 800 2cycle at 32to1, they use 5mm jets and after you figure out your jetting please repost back if that helps or you just got a lemon. thaks the actionator
     
  4. mew905

    mew905 New Member

    Joined:
    Sep 24, 2012
    Messages:
    647
    Likes Received:
    0
    yep, sounds like an air leak, which could mean you're not getting enough gas for your flow (clogged jet or something) or you simply have an air leak (which can happen, maybe your intake is shaking off?).
     
  5. graydog8josh

    graydog8josh New Member

    Joined:
    Nov 23, 2012
    Messages:
    447
    Likes Received:
    0
    the offset intake i got wasnt completely round, i had an air leak until i replaced it with the stock intake.
     

Share This Page