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Discussion Starter #1
Went riding today and my bike kept loading up at 1/4 throttle. Other than that it ran perfect. Made it tough to get up a couple hills with turns in the woods without stalling. I have a dyno jet needle in the carb with a 162 factory style main jet and mixture screw 2 1/2 turns. The needle is on the 5th clip. Just making sure here....I need to move the needle clip to either the 4th or 3rd position. I know nobody likes the dyno jet needle but my local yamaha dealer isn't open unti the 2nd so I can't get the right needle and run the 175 main jet. Any help would be apreciated.



mods are big gun race series system, cam mod, and air lid off.
 

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Yes, drop your needle down to the 3rd position.
 

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put your air box lid back on and wait until the 2nd when you can get a 180 main :rock
 

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Bansheekiller have you played with the Pilot jet??Or did ya just pop in a main jet?


LOW SPEED (PILOT) JET
The low speed (pilot) jet controls fuel flow at 1/8-1/4 throttle. The low speed (pilot) jet is usually not affected by most simple pipe/air filter modifications. However, a slightly lean low speed (pilot) jet can raise havoc in the winter where its fuel is added to the total mixture strength required to start. You may find going one level up will help a winter cold start situation.
Finally your idle mixture is revisited if you have a deceleration backfire situation. When you chop the throttle and use the motor to decelerate, if you get a stream of backfires, try increasing your idle mixture strength 1/4 turn at a time until the backfire goes away. Note: If you reach a point where your idle mixture is 4 turns out (for fuel type screws, NOT air type screws), try going up one size on the slow speed (pilot) jet and reset your idle mixture screw to 1-1/2 turns out and repeat the process.



Jeff
 

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I think that you are rich in the mid range, and should raise the clip on your needle to the 3rd spot and see what happens, you can't hurt anything.

But I bet it will run beter.

By no means do you ned the 180 main mentioned above.
 

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I Haven't heard any good thing about the dyno jet kits. Get rid of the dyno jet needle and go with the yamaha jet kit. that will clear up all your problems
 

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Discussion Starter #7
I did change the pilot jet to a 45. When I put the full system on I changed the pilot. The sputter is 1/4 throttle to almost half. The only time it does this is when your at low rpm and hit the throttle to almost half when the motor is under a load and hold it there. I'll go with parhump and nhyzf450's advice and move the clip up to the third notch.
 
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