Kawasaki KLR Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
63 Posts
Discussion Starter #1
Ive been doing a lot of reading on the deceleration after doing 22 cent mod or on the klr650 in general. Ive adjusted the needle to the best possible spot on my bike. great acceleration and running temps. Its taken a while but Im there. My question is. Is there a difference between deceleration popping and backfire? I get no backfire but usually at lower rpms when down shifting i get a bit of popping sound. My old bike did it all the time and I never cared,but I guess I kinda Got caught up in the subject being its a new klr!
 

·
Registered
Joined
·
895 Posts
........ Is there a difference between deceleration popping and backfire? .......
A "popping" sound wakes up the dog where as a "backfire" wakes up the neighborhood.

Are you just taking about a normal deceleration "pop" or is it more of a Harley type explosion where somebody calls the cops reporting gunshots?
 

·
Premium Member
Joined
·
3,206 Posts
The newer bikes have an air injection system which injects air into the exhaust to burn any unburned hydrocarbons thus reducing hydrocarbon emissions. That is what you are hearing on deceleration if your AIS hasn't been messed with. It is a normal sound. My AIS has been deleted and I get no decel popping.
JJ
 

·
Registered
Joined
·
63 Posts
Discussion Starter #8
Please correct me if Im wrong. I thought I read somewhere if you remove that system you will have a strong scent of fuel. Also by removing that do you gain anything or just lose some weight off the bike as well as the popping sound?
 

·
Premium Member
Joined
·
1,586 Posts
Not all that serious,

The AIS needs to be capped/ plugged off so it's not a source of fresh air getting in.
An exhaust gasket at either end of the headpipe'll cause a pop too.
It's not serious, but if it's happening all the time the exhaust or AIS is letting in
some 02 that pops when it hits the hot exhaust gasses. The other is a lean condition
when the throttle closes during non braking decel. At which time the carb is on the
idle circuit and jetting isn't the issue, but a lean idle mixture. Go out two turns for
a baseline start. I'm out 1 2/3 turns. Others get the smoothness around 2 2-1/4 turns
from gently seated.
 

·
Registered
Joined
·
63 Posts
Discussion Starter #10 (Edited)
I did 22 cent mod and Im about 2 turns out. I will have to check exhaust. Well.... I checked exhaust and the 2 manifold bolts were loose! LOL have to go ride to see if that made any difference,
 

·
Registered
Joined
·
6,635 Posts
My question is. Is there a difference between deceleration popping and backfire? ------------------------- I guess I kinda Got caught up in the subject being its a new klr!
I'll just be a wise acre,
Deceleration popping is "after-fire" in the exhaust. Loud explosion out the exhaust is still an "after-fire".

To me a true "Backfire" is back thru the intake port and air filter. Therefore the "Backfire Flame Arrester Screen" in the air box.
 

·
Registered
Joined
·
195 Posts
I get the mild popping on mine at 1.75 turn out, 2 and 2.5 turn out. Mine seems to run best at 2.5 t.o. I'm at about 250 ASL
 

·
Registered
Joined
·
63 Posts
Discussion Starter #14
I tried mine at 2 1/4 turns and it became sluggish and made loud bang when trying to start when cold with the choke. i seem to get the best acceleration and running at 2 turns.
 

·
Premium Member
Joined
·
3,206 Posts
Sorry for the delay NTS,
I don't think there is a smell issue with the removal of the AIS. If I had to do it again I am not sure I would bother removing it as I don't think it affects performance. I had just wanted to point out where the light popping under decel was coming from and that it is normal. Loud popping or backfire from the exhaust can indicate a leak in the exhaust system and should be investigated and repaired.
JJ
 
1 - 15 of 15 Posts
Top