Bonneville America Forums Forums Technical Forums Performance Mods America popping toooooo much

Need some input here. My 2002 America, pops excessively on deceleration, and lately its been popping when I pull in the clutch before I down shift. I had Bub slash cut pipes installed last year, and bike was not rejetted, but this problem has only started a couple of months ago. Yesterday, it was downright annoying. Bike is also not idling too well. Any suggestions.

Run some Seafoam (add four ounces to full tank) through the fuel system to clean the carbs, sounds you've got some gunk build up in there. A temporary solution would be to open the mix screws on the carbs a half to a full turn to get some more gas at idle and during deceleration.

Check the vacuum caps on the carbs, sounds like an air leak.
They dry out and crack over time. Also, check the torque on
the header bolts.

And while you're busy checking all of those things, take a little more time and check the condition of the rubber boots between the airbox/carbs and carbs/manifolds. Snug the clamps up too.

If you can't correct your lean condition by dialing out your fuel mixture screws, then you need to increase your pilot jet size.

1 way to check for a vacuum leak folks a can of carby cleaner while the bike is running spray a fine mist around the carbies and in lets if theirs a leak the rpms will increase when it sucks the cleaner in seems strange tho it was fine for so long with the bub's on

Thanks everyone, we will try your suggestions and get back with you, hopefully with good news.

question.....I've got my mixture screws out to 1.75...I know they have to come out a bit more....what's the max that you want to turn them out?

(stupid question time!!!!) They won't come out all the way and fall to the garage floor, will they?

I'm guessing that I should turn them out about 1/2 turn more.

I would try a 1/2 turn more out. You can go as far as 3.5 turns out, but if you're having to go more than 3, you probably need to go to the next larger pilot jets. And yes, if you keep turning out, they come out, but you shouldn't be going near that far.