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Discussion Starter · #1 ·
My YFZ 450 has a rough idle it will go blub blub blub and it will cut out for 2 seconds then idle again then repeat the process. Starts fine and everything but when It idles it idles rough. Also when I press the throttle from low to mid throttle it will studder going up in rpms. When Im ridding it it will pop on the very end of decel. Also when I press the throttle and then rev it it will pop then it will rev it will go pop and then reeeevvvvv. Then it will come down and pop once at the very end. Can the air fuel mixture have something to do with it?
 

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Discussion Starter · #4 ·
It started ever since I got the bike. It is carbed and it has the airbox lid off, aftermarket air filter, full exhaust system with baffle taken out but ever since the baffle has been taken out it runs the same. The guy said it was jetted. It's like it has low end throttle hesitation. It gets a little better when warmed up.
 

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Discussion Starter · #6 ·
What jets are stock and what jets are supposed to be in there for my mods?
 

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Discussion Starter · #8 ·
Yea there is I found it. Do I need to replace the all the jets or just the main and pilot?
 

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Discussion Starter · #14 ·
It's weird because it doesn't seem to do that while In gear only in neutral.
 

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Discussion Starter · #15 ·
I honestly think it's just the leak jet. Because the leak jet is stock causing the bog. And maybe a air fuel mixture screw adjustment for the idle problem
 

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I have been messing with my jetting recently too and I read a lot of threads on jet it's sounds to me like you are describing every symptom of running too rich from idle to 1/4 throttle. That means that you need to turn your fuel screw in. If it is already at less than 1.5 turns then go down a size on your pilot jet and adjust your fuel screw
 

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Discussion Starter · #17 ·
If you watch the video on YouTube Yfz 450 jumps. When he presses the throttle quickly then goes I can't do that on mine it will bog but not die. It will die sometimes but not all the time. I think it is the leak jet but I'm not to sure. I did the zip tie mod and it seemed to help with the throttle response a little but not with the throttle response right off the idle. Sometime it will pop and then rev up but not all the time. When your in first and do it in low throttle it will do it sometimes. But other times it won't it's like only if it's in a certain position.
 

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Discussion Starter · #19 ·
Jetsrus.com. anyone else have any input why I'm having this problem
 
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