Backfiring/Popping & Running Lean

naughtylion · December 8th, 2011, 11:23 PM

I've had a look around this site but can't really find a specific answer to my question - apologies if it's been answered before hidden away in another thread

I noticed my bike popping with the stock exhaust maybe once or twice in the two months I've had him. It was always in the morning when kicking over for the first time with the choke on.

I've since installed a yoshi slip on (completely aware this is for w@nk-factor only) and it's either started doing it more, or just become more noticible. I was wondering is this is an indication that it's running lean? It may sound great on a beasty engine, but with a loud exhaust IMHO this bike sounds better when it's running smoother and purring along, because the exhaust (although sounding better than stock) already highlights how tiny the engine is.

So my question would be (in the event that popping has no indication on lean/rich) is there any way to tell if your bike is running lean? Running lean will cause damage in the long run, right? I can't afford to rejet for a few months but if there's any indication I have that it's running fine I'd feel more comfortable about putting it, and the snorkel romoval, off for a while. But then again it happens more when downshifting to brake with the choke on in the morning, which would mean it's running richer... no?

Any help, as always, would be much appreciated. Thanks guys!

cuong-nutz · December 9th, 2011, 12:37 AM

The popping you are hearing is due to the kleen air system installed on your bike. You can remove it and plug it up and it will rid you of the popping. You may benefit from adding 2 washers under your carb needles.

You can find all the information in the DIY section here:
http://www.ninjette.org/forums/showthread.php?t=5586

Removing Kleen Air System
Shimming the Carb needles

Lots of good information to read and educate yourself

Alex · December 9th, 2011, 07:14 AM

/moved to new-gen tech

kenji_808 · December 13th, 2011, 02:45 PM

i have basically the same setup you have except i have a K&N drop in filter. I used two shims under my needles and it reduced the afterfiring a little and did increase power a bit, iirc majority of the 250s run lean from the factory, few are the exception.

i Just recently did the kleen air delete i now i have zero afterfires.

December 8th, 2011, 11:23 PM	#1
naughtylion ninjette.org member Name: Andrew Location: Sydney Join Date: Sep 2011 Motorcycle(s): 2012 Kawasaki Ninja 250R Posts: 35	Backfiring/Popping & Running Lean I've had a look around this site but can't really find a specific answer to my question - apologies if it's been answered before hidden away in another thread I noticed my bike popping with the stock exhaust maybe once or twice in the two months I've had him. It was always in the morning when kicking over for the first time with the choke on. I've since installed a yoshi slip on (completely aware this is for w@nk-factor only) and it's either started doing it more, or just become more noticible. I was wondering is this is an indication that it's running lean? It may sound great on a beasty engine, but with a loud exhaust IMHO this bike sounds better when it's running smoother and purring along, because the exhaust (although sounding better than stock) already highlights how tiny the engine is. So my question would be (in the event that popping has no indication on lean/rich) is there any way to tell if your bike is running lean? Running lean will cause damage in the long run, right? I can't afford to rejet for a few months but if there's any indication I have that it's running fine I'd feel more comfortable about putting it, and the snorkel romoval, off for a while. But then again it happens more when downshifting to brake with the choke on in the morning, which would mean it's running richer... no? Any help, as always, would be much appreciated. Thanks guys!

December 9th, 2011, 12:37 AM	#2
cuong-nutz RIP Alex Name: Cuong Location: Houston, TX Join Date: Apr 2011 Motorcycle(s): '10 250r, '09 265r Posts: A lot. Blog Entries: 2	The popping you are hearing is due to the kleen air system installed on your bike. You can remove it and plug it up and it will rid you of the popping. You may benefit from adding 2 washers under your carb needles. You can find all the information in the DIY section here: http://www.ninjette.org/forums/showthread.php?t=5586 Removing Kleen Air System Shimming the Carb needles Lots of good information to read and educate yourself __________________________________________________ HalfFast Racing Team Serving Greater Houston Area Riders:WFO Riders MotoHouston HPC CMRA Ride Smart Fastline Lone Star Track Days

December 9th, 2011, 07:14 AM	#3
Alex ninjette.org dude Name: 1 guess :-) Location: SF Bay Area Join Date: Jun 2008 Motorcycle(s): '13 Ninja 300 (white, the fastest color!), '13 R1200RT, '14 CRF250L, '12 TT-R125LE Posts: Too much. Blog Entries: 7	/moved to new-gen tech __________________________________________________ Montgomery Street Motorcycle Club / cal24.com / crf250l.org / ninjette.org ninjette.org Terms of Service Shopping for motorcycle parts or equipment? Come here first. The friendliest Ninja 250R/300/400 forum on the internet! (especially Unregistered)

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December 13th, 2011, 02:45 PM	#4
kenji_808 ninjette.org member Name: Justin Location: Ewa Beach, HI Join Date: Feb 2010 Motorcycle(s): 2009 CT Blue 250R(Sold), 2008 Black & Silver Honda CBR600RR(Current) Posts: 201	i have basically the same setup you have except i have a K&N drop in filter. I used two shims under my needles and it reduced the afterfiring a little and did increase power a bit, iirc majority of the 250s run lean from the factory, few are the exception. i Just recently did the kleen air delete i now i have zero afterfires.