Author Topic: running lean? pop! (Read 3977 times)

but bandit · « **on:** December 30, 2006, 10:42:39 AM »

Hi everyone

i went out for a ride on the bandit today, haven't been out too much in the winter maybe 3 or 4 times a week. anyway i'll get to the point, my exhaust has been popping when i slow down occasionally, not all the time. i think its called over run? unburnt fuel in the exhaust? anyway i was wondering why it would do this? anything to do with it being cold as it wasnt doing it in the summer? it still pulls fine through to the redline and other than this its runing pretty well. any help much appreciated.

thanks

Bartjan · « **Reply #1 on:** December 30, 2006, 12:51:10 PM »

if it is 'popping' from the exhaust i would think it is running rich instead of lean.

just check a spark plug to see what color it is:
- white = lean
- brown = good
- black = rich

but bandit · « **Reply #2 on:** December 30, 2006, 03:30:34 PM »

okey dokey, if i am running rich would i need to have a session on a dyno? also i mostly ride in the summer ,not the winter so if i get the carbs set up on a dyno for the conditions at the moment (cold!) will i have to get set up again for summer?
also how has my bike started to run rich?, its only started popping out the exhaust in the last couple of days and i'm wondering what would cause this?

thanks for the reply!

PitterB4 · « **Reply #3 on:** December 30, 2006, 04:07:13 PM »

Popping on decel is usally an indication of a lean condition. The bike will run leaner in the winter... cooler air is more dense. As long as it's pulling well, I wouldn't worry about it.

but bandit · « **Reply #4 on:** December 30, 2006, 05:23:33 PM »

Nice one pitter, thats the answer i was looking for!

it's still riding fine, and had a pretty enjoyable ride today, even though it was cold, but at least it was dry!

Bartjan · « **Reply #5 on:** December 31, 2006, 06:46:09 AM »

strange....

my bike was running lean (white plugs) and it never popped, last week i put bigger jets in it (from 110 to 130) which makes it rich (didnt have 120 yet) and it started popping sometimes when i went off the throttle

gsxr400 racer · « **Reply #6 on:** December 31, 2006, 10:44:47 AM »

the

Diet pop can be fiddled with by the fuel screws

gsxr400 racer · « **Reply #7 on:** December 31, 2006, 03:41:10 PM »

Quote from: "Bartjan"

strange....

my bike was running lean (white plugs) and it never popped, last week i put bigger jets in it (from 110 to 130) which makes it rich (didnt have 120 yet) and it started popping sometimes when i went off the throttle

There are two things you are looking at when doing a plug reading it will tell you how you are running on the bottom half and how you are running on the top half. The electrode is your main jet needle ect.. the outter part of the plug the wall surrounding your electrode were the threads are is your bottom fuel screws pilot jet ect...

if you are rich you blow flames out on decel and usually a pause a exhaust fart long pause exhaust fart ect... lean is on decel crackle , crackle, crackle , crackle ect.... there is a fine line between crackle and not takes some fiddleing or a dyno with air fuel set up!

but bandit · « **Reply #8 on:** January 09, 2007, 02:00:43 PM »

Hi guys, thanks for all the info. A few days after i wrote this the popping got worse and just as i was going down my road to go in my exhaust snapped at the manifold!

so now i have a new stainless steel exhaust on it and all my problems have been cured! thanks again

gsxr400 racer · « **Reply #9 on:** January 09, 2007, 05:18:13 PM »

LOL that was the last thing i would have thought about not being able to see or hear the bike!