Bonneville America Forums Forums Technical Forums Exhaust loud pop on ? side mid-range

i ocassionaly get a loud pop out of (i think) the right tor in 3rd or 4th when i'm at about 3000-3500 rpms rolling off the throttle..

i guess i'll have to check my air screws again. i think i have them at 3 turns. don't seem to have an air leak at the pipe clamp.

the bike has louder tors, drilled airbox, 130 mains. any ideas? carb sync? too rich too lean?

not sure if this belongs here or in mods?

thanks,

cat

Check the header pipe bolts into the head.

leaks, like said above, check entire exhaust system for leaks.

Right carb vacuum is different and your air screws are not set right. Go to 3.5 turns minimum up to 4 max. If you need to go beyond 4 turns then you need to increase pilot jet size. When the bike is set up properly you will get no popping on decel of any kind.

Hi Cat,

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...i ocassionaly get a loud pop out of (i think) the right tor in 3rd or 4th when i'm at about 3000-3500 rpms rolling off the throttle..

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Just the other day Vera started barking at me. Pulled over and low and behold one of the vacuum port rubbers was gone. Lucky me with my electronic issue, I had some of the 1/4 inch rubber nipples in my tool pouch. Check all of the vacuum ports to make sure those rubber nipples are air tight. Also, make sure your intake manifolds are tight. Spray some carb cleaner or such at them while the motor is running.

miniski was right about the header pipe bolts. they were loose. expand and contract. tightened them up and reduced popping/gurgling quite a lot. it did back fire pop once, but i really had to rev it up and roll off to get it to do it. so now i need to take off the right pipe and rtv it better. i'll also check the ballance pipe. isn't that pipe welded though? didn't realize there was a clamp on it...

thanks a lot guys.

cat