Join Date: May 2009
Location: Vancouver BC Canada
Exhaust backfire style loud pop and Idle adjustment.
I have been fighting this loud bang pop,like a backfire at the 2100 rpm area, like lots of cobra pipe purchasers here.Adding fuel in the 0 coloumn on my PCV ,new exhaust gaskets,acorn nut washers,testing for intake leaks,all the recommended areas of concern with limited or no success.
Then I read a coloumn in the VTX forum about checking for a fully closed Throttle plates at O throttle position as being an issue with cable controlled throttle bodies causing the same backfire bang issue.Then I was thinking about our idle adjustment and what happens when we move it up and down.We cause the electric servo to get a different voltage signal to either open or close the throttle plate to adjust idle to what we want.Lots of us want a lower idle to hear a lower rumble tone to our exhaust sound.
Reading ,that a lot of exhaust popping is caused by excessive fuel not completing a burn in the combustion chamber ,because of lack of air,then exiting into hot exhaust pipes and exploding due to air avaliability and heat,I made an adjustment.
So since I had my idle set to its lowest adjustment,I decided for an experiment to crank it back up to +100 rpm ,to open the throttle plates for more air intake at idle ,and off I went ,after playing all day with fuel maps.To my amazement no more loud exploding bangs at 2100 rpm whan I released the throttle either during cruise or down shifting blips.Just a bit of really mild popping once in awhile under 1500 rpm.
I could not believe my ears after weeks of frustration most of my issue was caused by my idle adjustment.I have "0'd out my 0 coloumn in my PCV now so I have no more fuel smell everytime I come to a stop and have readjusted my idle to the "0" neutral postion and all is great with my Cobra Scallop tip pipes now.Well for now.Obviously will have to ride for a month or so and see how it goes ,but it looks like an option some of you may want to try and see if it cures your popping or loud bang in the exhaust issues.Just that little extra air at idle position seems to of helped a lot.
Last edited by ta-kid; 05-25-2013 at 10:04 PM.