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2 Stroke Carbi Question

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This topic contains 26 replies, has 0 voices, and was last updated by  Mal 15 years, 3 months ago.

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  • January 21, 2010 at 8:22 am #97940

    Mal
    Member

    Riding around the paddock today my bike ‘coughed’ on rises where the bike lifts off the ground. It did this last week but I was low on fuel and switched to reserve and all was good.

    Today it was going fine for about 10mins and then had a couple of these ‘loss of power coughs’ on small jumps and rises. It feels like the fuel stops flowing into the carbi and then when it settles back on the ground it’s fine. Took it down on the flats and reved it in the first three gears and not a hint hessitation, then up on the parts where the bike can leave the ground and it does it again.

    I’m thinking there is something not working right in the carbi, but thought I would post and see if anyone had some ideas of where to start. I wont get to do any work on the bike now until Sunday or Monday.

    Thanks in advance.

    January 21, 2010 at 8:29 am #169012

    Dean
    Member

    Has to be floats or float height,probably a touch high and the tang needs bending a little. (maybe) :laugh:

    Ollie

    January 21, 2010 at 8:36 am #169013

    Anonymous

    Dick would pull the carburettor of strip clean and blow everything out count the jets out and write it down the number of turns so you can put it all back the same and check the float level at the same time
    Dick thinks your float level should not change but worth checking Dick would maybe lift it a mm or two not more as Dick said if it was ok before it does not just change last resort maybe.
    As an after thought Dick would pull the pick up from the tank does the bike you have run a screen worth a check also

    January 21, 2010 at 8:39 am #169014

    Greg
    Member

    Ollie wrote:

    Quote:
    Has to be floats or float height,probably a touch high and the tang needs bending a little. (maybe) :laugh:

    Ollie

    I agree with you Ollie sounds like that but and I dont want to say this but as Dick (giggle) said why would it just change all of a sudden :blink:

    January 21, 2010 at 8:54 am #169017

    Dean
    Member

    could also be a partial blockage in the pick up tube(the really fine holes in the bottom of the main jet.
    heres my theory :dry: As you are leading up to go over a jump ,you will probably be on the needle or the main,as you hit the jump you chop the throttle,because the bike will be doing a few revs and then goes into the throttle off position this essentialy leans the mixture to much which causes the bike to cough. This is just a stab in the dark but as dick said all should be revealed when the carby is pulled apart (maybe) :dry:

    I got nuthin :laugh:
    Ollie

    January 21, 2010 at 8:58 am #169019

    Jeffrey Smith
    Member

    Doesn’t have a side stand cut out switch does it?

    January 21, 2010 at 9:02 am #169018

    Mal
    Member

    Yeah I wouldn’t think the float level would change all of a sudden. But I’ll check it anyway.

    Dick has some good points. I was thinking along the lines of fuel supply to Dick. As it never did it before I switched to resever and that’s the first time I have used reserve, so a bit of crap maybe restricting flow at the time of zero gravity.

    Thanks guys.

    January 21, 2010 at 9:05 am #169021

    Mal
    Member

    Jeffro wrote:

    Quote:
    Doesn’t have a side stand cut out switch doea it?

    No it’s a Husky Jeffro, it doesn’t have much at all. :laugh:

    But good thinking Jeffro. Thanks :)

    January 21, 2010 at 9:06 am #169023

    Jeffrey Smith
    Member

    You sure, I thought they were required for ADR compliance.

    January 21, 2010 at 9:11 am #169024

    Greg
    Member

    It must be something along the enduro lines Jeffro cause KTM’s dont have them, yet DR’s KLR’s etc do your right
    Mal’s husky most definitely doesnt

    TB

    January 21, 2010 at 9:15 am #169020

    Mal
    Member

    Ollie wrote:

    Quote:
    could also be a partial blockage in the pick up tube(the really fine holes in the bottom of the main jet.
    heres my theory :dry: As you are leading up to go over a jump ,you will probably be on the needle or the main,as you hit the jump you chop the throttle,because the bike will be doing a few revs and then goes into the throttle off position this essentialy leans the mixture to much which causes the bike to cough. This is just a stab in the dark but as dick said all should be revealed when the carby is pulled apart (maybe) :dry:

    I got nuthin :laugh:
    Ollie

    I like your theory Ollie. Theory are good, almost engineer speak.

    Quote:
    you will probably be on the needle or the main

    :ohmy: on the main!!My main jet will be squeaky clean. I fact I might take it out and plug the hole as I have no need for it. :laugh:

    January 21, 2010 at 9:18 am #169025

    Mal
    Member

    Jeffro wrote:

    Quote:
    You sure, I thought they were required for ADR compliance.

    I believe the bike has to have an auto retract stand or a cut out switch on the stand for ADRs. Mine has an auto retract to the mid postion (only swings up half way). The Sherco has bruised my leg in the past as it comes up real quick.

    January 21, 2010 at 12:25 pm #169026

    Bruce Curtis
    Member

    TB, Ollie, and Dick have set you on the right path there young Mal withthe float and or suspect crappola in float bowl, I’m less inclined to believe the tank pickup is getting obstructed as the bike will run for a fair distance on the residual fuel in the bowl. However if it was coughing and stuttering on long steep uphills I’d be going for tank issues, but over jumps and whoops this is quite common on smokers that have an incorrect float height and yes they go out of adjustment as the needle and seat wear a little or just plain vibration and terrain, but this can be mimicked by a larger piece of detrius in the bowl temporarily blocking the fuel in some way.

    January 21, 2010 at 12:28 pm #169022

    tim
    Member
    Post removed

    There are some simple rules in the tech help section Medogrocket please read here and familiarise yourself with them

    whoops I have been a bad boy!!

    Give me a call Mal if you need any help

    January 22, 2010 at 11:18 am #169033

    Mal
    Member

    Mr Blue wrote:

    Quote:
    TB, Ollie, and Dick have set you on the right path there young Mal withthe float and or suspect crappola in float bowl, I’m less inclined to believe the tank pickup is getting obstructed as the bike will run for a fair distance on the residual fuel in the bowl. However if it was coughing and stuttering on long steep uphills I’d be going for tank issues, but over jumps and whoops this is quite common on smokers that have an incorrect float height and yes they go out of adjustment as the needle and seat wear a little or just plain vibration and terrain, but this can be mimicked by a larger piece of detrius in the bowl temporarily blocking the fuel in some way.

    Thanks Mr Blue thats all good stuff. I’ll check all that when I take the carbi out on Monday.

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