Motorcycle Repair: Popping noise while in idle, stock air filter, suzuki sv

Question
QUESTION: I have a 2003 Suzuki SV 650S.  It makes a popping noise when idling.  I believe it's coming from the intake.  Please help me with this if you can.  I changed out the spark plugs and it's still making the noise.  What do you think I should check into?  I appreciate any advice you can give me.  Thanks again!

~Eric

ANSWER: Hello, Eric. If the bike only makes the noise at an idle - and you still have the stock air filter and stock exhaust - it is possible that you are hearing a backfire through one or both of the cylinders. You need to do some troubleshooting first before money is spent and parts are replaced.

Is the bike hard to start when cold and when hot? Have you noticed an increase in fuel consumption and a loss of power? Chances are then that the carbs need tuning and/or the air filter needs replacing. When you removed the original spark plugs, what did they look like? If they were very black and sooty, the carb(s) are set too rich. If they are white and glazed looking, the carbs are probably set too lean and the motor is running too hot.

You might want to check with the tech forum at an owners group dedicated to the SV650, like this one: http://forum.svrider.com/

---------- FOLLOW-UP ----------

QUESTION: Thank you so much for the email.  It was helpful.  The bike is not hard to start when its hot or cold.  I do notice the popping noise starts when the running temp reaches around 180 - 200 degrees while idling.  When I pulled out the spark plugs, they were a light brownish glazed color.  From your previous response I am thinking maybe the carbs are set too lean. What do you recommend I do to fix this??  Thanks again for all your help!

-Eric

Answer
I forgot to ask if you replaced the stock exhaust with a low restriction aftermarket one. If so, you need to retune the carbs to match the exhaust or the bike will run lean. If, however, you still have the stock exhaust it is possible the carbs need attention anyway in the form of a synchronisation session.
A light tan to medium brown colour on the spark plug tips indicated normal operation, but if they are glazed as you say then the carbs need a bit of tweaking. If your bike has never had a carb synch since 2003, it is definitely due. Might be worth your while to have the dealer or a reputable bike shop have a look.