decel popping
#1
10-28-2007, 10:49 PM
Join Date: Oct 2007
Location: Connecticut
Posts: 302
decel popping
I know this subject has been covered before on this forum, but here's my problem. I've been getting a lot of decel popping from my bike. I'm guessing its a tad rich. My mods are in my signature and the air/fuel screw is 2 1/2 turns out. Any guesses or advice would be appreciated. Thanks- JOSH
#3
10-29-2007, 01:07 AM
Join Date: Jun 2007
Location: La Luz, NM (Yes, I'm a LaLuzer now)
Posts: 255
RE: decel popping
The decel popping can also be caused by a leak, especially if you have a slip-on.Run your fingers around that joint as soon as you start a cold engine. If you feel air pull it apart and put it pack together with black high permatex silicone. Also, the smog system contributes to decel pop.
#4
10-29-2007, 03:13 AM
Join Date: Oct 2007
Location: Connecticut
Posts: 302
RE: decel popping
Thanks guys. Fireroad i don't think its a leak only because it was doing it when i had the stock exhuast on too. I'll check it anyways.
#5
10-29-2007, 04:33 AM
RE: decel popping
I don't know what kind of difference this "smog" stuff is, but I do know that I unhooked the vacum line to the carb (and capped both ends) so that it was inoperative. On my ride home the decel popping was HORRIBLE!!! I hooked it back up, and now it has hardly any popping. So whatever this smog stuff does, I'm leaving it on there hooked up like it shouldbe. I just don't need some old lady having a heart attackwhile I'm downshifting up to a stoplight. It sounded like gunfire! It runs perfect. And by the way, I "felt" no difference in power, plus or minus, just the annoying popping. My bike is modded, but this thing is staying put!
#6
10-29-2007, 07:42 AM
RE: decel popping
Something doesn't sound right about that. Are you sure you had good plugs on the carb nipple and reed valve on the front of the cylinder head? My air suction system has been disabled (plugged) for a over year with no issues what-so-ever.
ORIGINAL: zapitbullseye
I don't know what kind of difference this "smog" stuff is, but I do know that I unhooked the vacum line to the carb (and capped both ends) so that it was inoperative. On my ride home the decel popping was HORRIBLE!!! I hooked it back up, and now it has hardly any popping. So whatever this smog stuff does, I'm leaving it on there hooked up like it shouldbe. I just don't need some old lady having a heart attackwhile I'm downshifting up to a stoplight. It sounded like gunfire! It runs perfect. And by the way, I "felt" no difference in power, plus or minus, just the annoying popping. My bike is modded, but this thing is staying put!
I don't know what kind of difference this "smog" stuff is, but I do know that I unhooked the vacum line to the carb (and capped both ends) so that it was inoperative. On my ride home the decel popping was HORRIBLE!!! I hooked it back up, and now it has hardly any popping. So whatever this smog stuff does, I'm leaving it on there hooked up like it shouldbe. I just don't need some old lady having a heart attackwhile I'm downshifting up to a stoplight. It sounded like gunfire! It runs perfect. And by the way, I "felt" no difference in power, plus or minus, just the annoying popping. My bike is modded, but this thing is staying put!
#7
10-29-2007, 01:30 PM
Join Date: Oct 2007
Location: Connecticut
Posts: 302
RE: decel popping
I thought the popping sound was due to extra fuel igniting somewhere in the exhaust. I believe you guys that I may be lean, but can someone explain to me why it "pops" if it wasn't getting enough fuel? Thanks- JOSH
Could it be a possible vacumm leak too?
Could it be a possible vacumm leak too?
#8
10-29-2007, 04:19 PM
RE: decel popping
Back firing is lean.
After firing is rich.
I dont know which you have but your jetting soundsin the ballpark except:
I dont think the 40 pilot & 2.5 turns go hand in hand. I ran 2.5 turns on the stock pilot. The 40 + 2.5 turns may make you rich & make you have after firing. The purpose of the smog stuff is to inject air into the exhaust pipe to help burn any unburned fuel. If you were rich you would have unburned fuel & afterfiring. If you hook it back up & it gets better it may be burning your excess fuel & stopping the afterfiring.
Might be worth turning you fuel screw in a bit.
After firing is rich.
I dont know which you have but your jetting soundsin the ballpark except:
I dont think the 40 pilot & 2.5 turns go hand in hand. I ran 2.5 turns on the stock pilot. The 40 + 2.5 turns may make you rich & make you have after firing. The purpose of the smog stuff is to inject air into the exhaust pipe to help burn any unburned fuel. If you were rich you would have unburned fuel & afterfiring. If you hook it back up & it gets better it may be burning your excess fuel & stopping the afterfiring.
Might be worth turning you fuel screw in a bit.
#9
10-29-2007, 05:34 PM
RE: decel popping
ORIGINAL: KLXer
Back firing is lean.
After firing is rich.
I dont know which you have but your jetting soundsin the ballpark except:
I dont think the 40 pilot & 2.5 turns go hand in hand. I ran 2.5 turns on the stock pilot. The 40 + 2.5 turns may make you rich & make you have after firing. The purpose of the smog stuff is to inject air into the exhaust pipe to help burn any unburned fuel. If you were rich you would have unburned fuel & afterfiring. If you hook it back up & it gets better it may be burning your excess fuel & stopping the afterfiring.
Might be worth turning you fuel screw in a bit.
Back firing is lean.
After firing is rich.
I dont know which you have but your jetting soundsin the ballpark except:
I dont think the 40 pilot & 2.5 turns go hand in hand. I ran 2.5 turns on the stock pilot. The 40 + 2.5 turns may make you rich & make you have after firing. The purpose of the smog stuff is to inject air into the exhaust pipe to help burn any unburned fuel. If you were rich you would have unburned fuel & afterfiring. If you hook it back up & it gets better it may be burning your excess fuel & stopping the afterfiring.
Might be worth turning you fuel screw in a bit.
I took mine off and have great success with it. Note though that when I drilled the baffle plates in the exhaust i heard a little more popping, and then when I put the Muzzy on it was even lotuder, but not bad. I think its pretty norrmal but my popping could be different from yours.
#10
10-29-2007, 10:21 PM
Join Date: Oct 2007
Location: Connecticut
Posts: 302
RE: decel popping
Note though that when I drilled the baffle plates in the exhaust i heard a little more popping, and then when I put the Muzzy on it was even lotuder, but not bad. I think its pretty norrmal but my popping could be different from yours.
I am going to play with the mixture screw though too see if that helps any.
Also...what is the difference between back firing and after firing?