backfire thru the airbox

[09XB12Ss]

My stock 09 Xb12Ss also does it when I downshift. I only use premium and have the breather re-route. It's the only bike I've ever had that does this.

[teh Nub]

My 06' Ss does it when down shifting/rev matching withing the first 10 minutes of riding. I have the breather reroute, "white wire" mod via ecmspy, have reset my TPS and AFV etc.

When I first got my bike used, idle was set at around 1300 rpm or so, when I did my first TPS reset it came out to about 900 rpm 4.6 deg / 5.1% and I just left it there.

A 12-16 ounces can of octane booster will only raise octane 2-3 *points*, I.e. from 92 to 92.3. It's not going to make any difference, but if it did, you would need to retune to see any power difference. Gasoline octane isn't nitrous oxide...

[zero]

True octane is just a constituent molecule of gasoline. Like its close neighbors heptane and nonane. It does not do a single thing at all to any power in any vehicle. What it does is reduce detonation. Octane has a way of stabilizing fuel under pressure. The best you can hope for with high octane gas is good combustion. Which might fix up an intake fart electronically?

Adding octane boost to your tank when running proper octane gas indicates a problem with the engine or gas. As well as its more polluting and usually illegal for on road use.. .. well.. like every squid's muffler.

[TMC]

Well I run a straight pipe don't care if it's illegal or poluting. It pulls like a train up in the power band. I also had a bad backfire prob finally did the breather mod and smoothed it out big time.

[zero]

breather somehow does the trick for some.

OT:
Its not only illegal and noise/air polluting.. Its also why people generally hate motorcycles and motorcyclists. I have to catch flack, attitude and road rage from YOUR rudness.
But as long as you're the only person on the planet. I guess its fine.
I don't mean to come on the board and instantly start flaming. But it amazes and disgusts me all the bike and truck fans for that matter that see no problem in making all that racket. Yet.. I bet if I stood outside your window with a bullhorn screaming all day.. you'd think me rude. Then these same tools ride up in their flip flops and t shirts and try to ride 2 feet off my tire or get me to ride in their weekend noise-a-thon. Nothing but contempt for them.
I was a kid once.. but if you're 25+ there's no excuse

Its not a race track.. its not a bike show. Its the road and its rude.

[TMC]

Are you from Cali??? Or up north??

[firechickenXB9R]

Sorry

but would like like some CHEESe with that WINE!!!!!!

<Loud Pipes Safe Lives>

[TMC]

O and if you don't like loud badass sounding bike you should give your Buell to some one who like a badass bike and you can go buy a scooter

[Roccodart440]

Mine backfires or "sneezes" through the throttle body when blipping the throtle on a downshift.

[Bill2]

The reason they "sneeze or backfire through the intake is there set a little lean off idle from the factory to help meet epa pollution specs. The carburated sportsters started doing the same thing a few years back for the same reason to meet epa specs. The simple cure is is to richen the air/fuel a little off idle, on the carbed sportsters most installed a larger pilot jet and adjusted the a/f screw. On the fuel injected sportsters and buells it takes something like ecmspy to richen up the a/f mixture but the rerouting of the breather hoses helps a lot and is super easy and reversible if need be for inspection. Both will make it run a lot smoother BTW the factory only does this to meet epa ever tightening standards not for the good of the engine! There tring to keep air cooled engine bikes around as long as possible but even lawnmowers will be watercooled in a few years.