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Hey guys I am having a problem with getting the correct jetting on my 05 yfz450. I currently am running a Namura stock compression piston, fmf power bomb header, fmf q4 exhaust, Uni air filter with the lid on, and stage 1 hot cams. I have the virus's jet kit and needle please help with your recommendation. I am at sea level
 

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I don't think you are going to find much help due to the jet kit you are using. I have not heard of that one. Most folks just use standard jets and the NCVQ needle.

If you want to go that route I would start at 45 pilot, fuel screw 1.5 to 2 turns out, 168 main, NCVQ needle third clip (from the top). Keeping the lid on adds a fair amount of restriction. I would remove it if possible. With this setting, you will most likely have to test out the main...may have to go up to 170 or so. Also may need to go to 4th clip on the needle. But the settings I gave should get you in the ball park.
 

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Personally I would use genuine Keihin jets. They will have a "K Star" stamping on them. I would order them individually: Main 168 & 170, Pilot 45, and NCVQ needle. That should get you in the ballpark for the mods you have.
If you are not familiar with jetting, there are articles at the top of the forum that explain it. Check out the “the MOTHER FCR tuning / INFO thread.”
Also if you are suffering from the “bog” when you stab the throttle hard, I would change your leak jet to a 35 and do what they call the “Zip Tie” mod. I had that problem and instead of the Zip Tie mod, I added a stiffer accelerator pump spring and adjusted my accelerator pump shot until it was gone.
 
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