Popping way bad on deceleration

JayJay

JayJay

New Member
im up against the ropes on this one. 07 k9, 117 motor, Vance and Hines big radious pipes. Word is mixture needle should be out 11/4 to 1/12 ball park. I noticed mine is out almost 3 turns. I do notice raw fuel in the exhaust when I first get it out of the garage, but it runs very nice. Problem is when I bring the needle in closer to text book settings, bike pops and cracks terrible on deceleration. Carb is jetted correctly with a 32 mid jet, and I've done the intake leak test useing carb cleaner. Doesn't seem to have any. Any help would be great. Also are these pipes known to be bad for that. I'm assuming I'm running it really rich just to stop the decel pop !
 
JayJay

JayJay

New Member
Good info, I guess I'm making more of it than it is, I guess run her a little fat or let her pop !
Not running baffles definetly seems to play a big part. Thanks guys.
 
Kobi

Kobi

Member
Three turns out on the mixture and raw fuel in the exhaust would indicate you have issues. Are you three turns out to have a nice idle, or to reduce the popping? How do you see the raw fuel in the exhaust and where?
 
BWG56

BWG56

Guru
JayJay said:
im up against the ropes on this one. 07 k9, 117 motor, Vance and Hines big radious pipes. Word is mixture needle should be out 11/4 to 1/12 ball park. I noticed mine is out almost 3 turns. I do notice raw fuel in the exhaust when I first get it out of the garage, but it runs very nice. Problem is when I bring the needle in closer to text book settings, bike pops and cracks terrible on deceleration. Carb is jetted correctly with a 32 mid jet, and I've done the intake leak test useing carb cleaner. Doesn't seem to have any. Any help would be great. Also are these pipes known to be bad for that. I'm assuming I'm running it really rich just to stop the decel pop !
Click to expand...
Read this maybe it will help
 

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JayJay

JayJay

New Member
3 turns out to stop the popping, it will run fine tunning per s&s instruction, just pops on decel like crazy there. Bike has been like this since the 640 lift cam install. When I say raw fuel I mean you can smell it in the exhaust only when it is cold. Once warmed up you don't notice it. Also exhaust gaskets and such seem to be just fine.
 
cdogg556

cdogg556

Guru
I run a 78 main and a 32 idle, air mixture screw out 2 3/4 turns, baffles cut in half, no popping at all and still loud as hell and faster with the half baffles in then without.
 
Fat_Bastard

Fat_Bastard

Active Member
Sometimes popping on decel is a sign it is running a little lean on the bottom end...

Richen it up to see if it goes away,
Best way is to temporarily test for a few seconds on DECEL ONLY by:
Ride it around after warmed up (5 minutes) put it into a closed throttle decel from say 2nd or 3rd gear for a good distance from mid level to high RPM and as soon as you let off the throttle pull up a little on the choke lever to create a richer condition, bring it down to about a thousand RPM; if this stops the popping then you know what to do -- go richer on the bottom end... (air screw, pilot jet, etc.).

PS: Check your air cleaner for holes, gaps incorrect seal too.
 
JayJay

JayJay

New Member
cdogg556 said:
I run a 78 main and a 32 idle, air mixture screw out 2 3/4 turns, baffles cut in half, no popping at all and still loud as hell and faster with the half baffles in then without.
Click to expand...
Yours seems to be on about the same settings as mine, which mine doesn't pop and go on at 23/4 eather, so maybe running on the rich side is ok, just enjoy and stop fretting about the needles setting not being text book.
 
Gmutoagrsv

Gmutoagrsv

Active Member
What’s your elevation? I’m at about 5500 and had similar issues. Or did you get it straightened out?


Sent from my iPhone using Tapatalk
 
JayJay

JayJay

New Member
Elevation 978, still have the problem, replaced the needle, rebuilt the carb. Still have to run rich.
 
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