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Discussion Starter · #1 ·
I just put on my ct exhausrt system and i jetted the carbs as per the instructions and it is popping when i let off of the gas. Any ideas??? Is it running to lean ?? I put 170 175 jets in the carbs.
 

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Any mods to the airbox? What size pilot jets are you running? How many turns on the air/fuel screws? Do you have aftermarket needles and what clip setting are you running? Usually the popping on decel means you either need larger pilots or if the pilots are large enough you need to turn your fuel screws out a bit.

I'm sure Willy or MD will speak up and either correct me or add to this.
 

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Discussion Starter · #3 ·
It's an aftermarket aluminum airbox w/ no lid. I'm using the 95 pilot jet and the c-clip is on the the second from the top goove. the fuel screw is 3 turns from seated and i'm using ct titanium needles. my elevation is 817 ft above sea level.
 

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It's an aftermarket aluminum airbox w/ no lid. I'm using the 95 pilot jet and the c-clip is on the the second from the top goove. the fuel screw is 3 turns from seated and i'm using ct titanium needles. my elevation is 817 ft above sea level.
You will need 160 to 165 mikuni mains, aftermarket needles about half way up, and #25 pilot jets..........
 

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Discussion Starter · #5 ·
The exhaust is also starting to turn blueish right by the head.


You will need 160 to 165 mikuni mains, aftermarket needles about half way up, and #25 pilot jets..........
 

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The exhaust is probably going to change colors a little bit by the head from the heat if its brand new. At night your headers may even glow red because the aftermarket exhausts are usually thinner. Just as long as you are jetted right I wouldn't worry about it.
 

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Discussion Starter · #8 ·
You will need 160 to 165 mikuni mains, aftermarket needles about half way up, and #25 pilot jets..........
Worked great, rode it for an hour yesterday. Just need to ride it a couple more times and check the plug but thanks for the help Willykiller.
 

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You want a slight / soft popping under decleration. It is a sign of a lean pilot / idle circuit. If it is rich enough that it doesnt pop slightly then it is way rich when it is Idling.

High RPM with the throttle closed should cause a lean condition. If it doesnt then your to rich. When your riding or just cruzing along at 1/4 throttle it will not be lean cause the throttle is slightly open.

Using my wide band o2 meter I would get a slight popping on deceleration with a 12.5-13.0 :1 AFR measured with the raptor idling. When decelerating i would get a soft popping sound and the AFR would go past 15:1 like it should. When cruzing on the pilot circuit it would go from 13.0:1 and make its way to 12.5-12.2:1 as you gained rpm while riding at or around 1/4 throttle.
 

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You want a slight / soft popping under decleration. It is a sign of a lean pilot / idle circuit. If it is rich enough that it doesnt pop slightly then it is way rich when it is Idling.

High RPM with the throttle closed should cause a lean condition. If it doesnt then your to rich. When your riding or just cruzing along at 1/4 throttle it will not be lean cause the throttle is slightly open.

Using my wide band o2 meter I would get a slight popping on deceleration with a 12.5-13.0 :1 AFR measured with the raptor idling. When decelerating i would get a soft popping sound and the AFR would go past 15:1 like it should. When cruzing on the pilot circuit it would go from 13.0:1 and make its way to 12.5-12.2:1 as you gained rpm while riding at or around 1/4 throttle.
You dont want to be cruising at 13-1.. try going a tad leaner like 14.7 cruising. Also on decel leaning it out past 15 is fine... Hell a car on decel goes to 17. You want just enough fuel to where its not popping.
 

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If it inst poping at all on deceleration your going to be way richer than 13:1
 
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