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Jetting on stock Carbs need some advice

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    Jetting on stock Carbs need some advice

    I know this question has been asked a trillion times but i actually don't want to modify my bike I'm not adding pods and I'm not adding exhaust.

    that being said here it goes
    So today we went on a ride and the bike was running normally, but as we filled up i checked the gas mileage, my bike used to get around 40mpg but now its getting around 25-28mpg. Later on the 240mile trip the bike started developing a miss at cruising speed. I got home disassembled the air box, carbs, and boots. The carb boot O rings are shot someone put silicone them they are flat, that's a definite need. Since the carbs got taken off they are at least getting new gaskets, o rings and dipped. my question comes to the jets, someone has upped the jets, not me and I do not know why, when ect. They were like this when i got it.
    The Main jet has been increased to a 120,
    The pilot jet has been increased to 45
    The air jet is has been increased to 180

    Question is do i need to return back to stock jetting or leave alone? The only air flow modification I have is a K&N air filter. stock air box, stock exhaust. I could easily change the jets but would I sacrifice/gain anything doing that?
    Also one thing to keep in mind is my engine is an 1100g in a 1000g

    I also need the new O Rings for the intake so do i buy for a 1100 or 1000g?

    #2
    Your last question is the easiest. The 1000 and 1100 o-rings are the same kit.

    The stock main jet is 115.
    The stock pilot jet is 40.
    The stock air jet is 160.

    With today's oxygenated fuels, a step up in jetting is not a bad idea, but it's hardly worth the effort just for that. Your K&N filter might lean it ever so slightly, so I would probably just go to a 117.5 on the main.

    Regardless of what happens at full throttle, there is NO extra air going through the system at idle and low-throttle situations, so there should be no need to increase the pilot jet.

    About the only good news here is that the extra size on the air jet might be ofsetting the extra fuel on the main, which might have balanced it out a bit.

    If it was MY bike, I would go to stock 40 pilots, 117.5 mains and maybe a 170 air jet.

    .
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      #3
      Thanks Steve,
      the reason I asked is because I already have the jets I listed, I also have a huge amount of stock jets in the parts that bought and I didn't know if it would be worth me switching back to stock jetting. I believe I found a few 170 air jets but I will continue to search for others and see what I can find. I couldn't find any 117.5 mains

      I guess my next question would be is a 120 main, 170 air, and stock 40 pilots a good combo?
      Thanks for the info
      Last edited by Guest; 07-27-2016, 01:16 PM.

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