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Discussion Starter #1
I have a slight sputter when I'm just going up and down my street at in between barely any throttle and 1/4 throttle. You know just cruising at around 5-10 mph. Any theories?? I know its a carb issue and a slight one at that. My carb setup is airbox with no lid. K&N with plate, 170/175 mains, 25 pilots, screws turned out 3 full turns each.
 

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Have you cleaned the carbs recently? From what I've learned on the forum it could be a clogged pilot jet. Also make sure the tip of a fuel screw didn't break off while adjusting and block the hole in the carb off completely. And one last thing that happened to me was a malfunctioning choke plunger causing the choke to remain partially on no matter what the lever position was.
 

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Discussion Starter #4
sounds like a dirty pilot
I actually just put the pilots in. I don't think they would be dirty. Do you think my fuel screw turn settings are good. I just talked to a dude at CT racing and he said he does them a 1/2 off. left side 3 turns right side 3.5 turns. What do you think?
 

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Discussion Starter #5
Have you cleaned the carbs recently? From what I've learned on the forum it could be a clogged pilot jet. Also make sure the tip of a fuel screw didn't break off while adjusting and block the hole in the carb off completely. And one last thing that happened to me was a malfunctioning choke plunger causing the choke to remain partially on no matter what the lever position was.
carbs are spotless. I will check the fuel screw tips though. The choke seems to be working fine. Don't get me wrong the bike runs like psychotic cheetah. I just noticed this when I was running up and down the street with my daughter on with me. I thought I would ask even though that area of throttle isn't usually accessed for very long. :eek:
 

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Discussion Starter #7

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I did mine at 1 1/2 out on left and right and it runs great but of course every raptor is different. I did manage to break a tip off a fuel screw after going full tight to begin my count out. I didn't realize it until I went to install a set of Vito's finger adjustable screws and noticed to tip sticking through the carb after I removed the screw...Those little F'ers break off easy. lol
 

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Discussion Starter #9
I did mine at 1 1/2 out on left and right and it runs great but of course every raptor is different. I did manage to break a tip off a fuel screw after going full tight to begin my count out. I didn't realize it until I went to install a set of Vito's finger adjustable screws and noticed to tip sticking through the carb after I removed the screw...Those little F'ers break off easy. lol
yep. I think I read about this issue on Allen Hvac's thread. Like ongoing for years trying to figure out what the problem was. Crazy! 1 1/2 on both? Is your jetting similar to mine?
 

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i didn't say to change the main i said turn the screw out on the side with the bigger main:confused:
 

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He did say to increase the fuel delivery on the side of the bigger main, how does it run with the fuel screws set at 2 turns........
 

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Yea sorry about that. I miss read your post tommy.

I would still try 2 turns out on each.
 

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Discussion Starter #14
what about 2 and 2.5? also i've noticed some popping on deceleration. not a lot, and after i shut the bike off i hear a small poomp pop out the exhaust. just once.
 

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If it's popping on decel AND stuttering at low throttle, simply turn the fuel screws both out 1/4 to 1/2 turn each (counter-clockwise) from their current positions.
 

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Or if it isnt then start to slowly turn them in. You want a slight poping on deceleration. Other wise your way to rich. With my wide band o2 meter I was getting a soft slight poping (not hard cracks like fire crackers) at around 12.5-13:1 AFR while Idling.

The poping is caused by a lean condition that occures when the throttle is shut and the rpm's are high and coming down (deceleration). If you get no poping then there is no lean condition. Deceleration should cause a lean condition. If it doesnt then your way to rich.
 

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yep. I think I read about this issue on Allen Hvac's thread. Like ongoing for years trying to figure out what the problem was. Crazy! 1 1/2 on both? Is your jetting similar to mine?
Yes I have 1 1/2 on both and I can't say they are 100% dialed in but Im not getting a sputter at 1/4 throttle. My full setup on this bike is in my signature...I'm a few steps down on jetting 160/165
 
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