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rich or lean?

Discussion in 'Technical and Troubleshooting Torque' started by ben1, May 25, 2009.

  1. hi all,

    i have another question, is it better for a bike to run rich or lean?
    and would this play apart in the bike starting easier or harder? if so what would make it start easier?


  2. Rich.
    Too lean and you start getting extremely hot combustion temperatures.
    Can lead to pre detonation and destroy cylinders, pistons, rods etc.

    Rich is safer.

    On that note, neither is good.
  3. Rich is safer for two strokes too thanks to the extra lubing being better than less.
  4. you can test if its running too rich

    rev the thing to 4000rpm
    and note any farting out the rear end as well as fluctuations in revs

    if its running rich it will be hard to keep it at that rev speed at a constant throttle without the rev needle jumping up and down, it will also smoke more out the exhaust and stink more

    on your across if its set too lean it will have problems starting also if too rich same thing, the trick is to get it right

    the 4 flat head screws on top of the carb, need to be turned clockwise to tighten them, do this to all 4, now your bike will be way too lean, turn each screw 1/2 a turn anti clockwise, to give it more richness, now try to start the thing, if it doesnt start, give it another 1/4 turn, try starting it with full choke, if the revs go up to around 3k and sit there its running good, if they go up then drop, its out, all screws must be turned the same amount, its trial and error, also reset the base idle to just under 2k when choke is off, the base idle screw is under the carb, or on the side of your bike sticking out of the fairing.

    once you get it right, the bike should start with choke in the morning, go up to 3k, when its ok, a couple minutes later, turn choke off and it should sit at just under 2k without the smog comming out the rear end.