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TTR250 air balancing

Discussion in 'Bling and Appearance' at netrider.net.au started by jeffatav, Apr 7, 2007.

  1. I have just given my recently purchased TTR250 a service that included a K and N filter to replace the foam filter.
    The bike has a staintune muffler and it sounds like there are no baffles in it.
    The air box has about five 25mm holes drilled into it to increase air flow, but I don't know what other mods are in it.

    I also changed the plug and a NGK cr8e came out and the recommended NGKcr9e was installed along with a new battery. Any difference in plugs????

    The trouble is I can't seem to get the air/fuel mix right and it doesn't idle well.

    I have now put back the original filter in an effort to regain the balance.

    Any other "tricks" I should know about???



    Cheers,

    Jeff
     
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  2. Did it idle before?

    The system sounds like its pretty free flowing so a fiddle with jets and needle could be in order. Does it make power or just more noise the harder you twist the throttle?
     
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  3. at the moment it will start with full choke and rev its tits off and then die when I put the choke in.
    can't get it to idle!
    time for a beer!!!!!
     
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  4. The K&N filter and staintune will make a huge change to it's breathing so your mixtures will be well out. As an ex mechanic I can't say I like K&N at all...... but if you're planning on offloading it before all the stuff that k&N's let through into your engine (dirt, dust, passing pedestrians) then I guess thats someone elses issue....


    Generally a motorbike carby needle has about 5 "positions" that can be used for adjustment, other than that you will need new carby jets.


    I cant say im a fan of "drilling holes in the airbox" to increase flow. Those things are designed with a lot of R&D and often the results are way worse when people do this, not better. I dont think that pronciple has worked properly since the early 80's :p


    Plastic trumpets put on a factory airbox to meet noise restrictions for a specific market though is a different matter.



    One range of plug shouldnt make too much difference.




    Any improvement just running the normal air filter?
     
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  5. see post above!!!

    I reverted back to how I found it with the foam air filter etc.
    I even checked the valve clearences, spark plug clearance, etc etc.

    It will start from cold with full choke and revs its tits off, but when I try to put choke in, she dies and doesn't want to start again.

    I am thinking almsot flooded type symptoms.

    Might have to see the pros!!
     
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  6. try some gaffa tape over the holes?
     
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