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500 EXC Backfiring - Bad thing?

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Got a 2015 500 EXC the other day. Whenever riding off of the throttle a bit, it likes to backfire and pop a LOT. 

Is this a bad sign or is this okay? 

Not really complaining because it sounds beautiful, just want to make sure there isn't anything wrong at all. Don't know anything about bikes mechanically really, just have been riding them my whole life and always pay people to work on them because I'm terrible with stuff like that lol.

Thanks! 

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Has it been modded to increase fueling? They are super lean stock, you'd expect a lot of popping on the overrun,.

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Secondary air injection. Theres a hose you plug with a bolt or emission kit that will get rid of that noise. I thought I liked the noise too but gets irritating after a while. 

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14 minutes ago, IDTrav said:

Secondary air injection. Theres a hose you plug with a bolt or emission kit that will get rid of that noise. I thought I liked the noise too but gets irritating after a while. 

So just to confirm - it's a normal sound and doesn't signify anything bad? 

Appreciate it a ton, thank you guys for the responses! 

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Posted (edited)
52 minutes ago, ximzinc said:

So just to confirm - it's a normal sound and doesn't signify anything bad? 

Appreciate it a ton, thank you guys for the responses! 

Nothing bad - it's just extra air going into the exhaust from that hose. In my S4 (automotive world) it helps warm the CAT up on cold starts - not sure if it would be the same for bikes but we don't have a CAT so not sure what the purpose is??? 

I replaced my stock pipe with an FMF and then took the reeds out so would assume you either have an aftermarket exhaust or end cap which is making the noise more audible now. 

Edited by IDTrav

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4 minutes ago, IDTrav said:

Nothing bad - it's just extra air going into the exhaust from that hose. In my S4 (automotive world) it helps warm the CAT up on cold starts - not sure if it would be the same for bikes but would assume so?

 

The hose going from the valve cover to the airbox, would benefit cold weather warmup, but none of the other stuff. But when the bike gets hot in 90 or 100 degree weather, that hot contaminated air, not so beneficial.

all popping  that can exist on the ktm is not necessarily all fueling, but stock lean  is bad with any modification , and normally produces severe decel pop.  Ive heard couple bikes with vortex Ecu's producing decel popping also, But a lot better than stock.

I had a 2003 DRZ open pipe, that thing never popped, only gurgled, even at extreme forced high rpm decel, not one pop.

 

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On 8/16/2019 at 5:09 PM, IDTrav said:

Nothing bad - it's just extra air going into the exhaust from that hose. In my S4 (automotive world) it helps warm the CAT up on cold starts - not sure if it would be the same for bikes but we don't have a CAT so not sure what the purpose is??? 

 

Injecting fresh air into the exhaust at the head is for emission reasons in this case. I believe it helps burn or convert fuel that isn’t consumed during combustion. 

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Our old RFS bikes were miserable to seal at the header with chronic backfiring. The mechanics said for years it's bad to inject cold air into the exhaust valves over time. We used any means possible to get  better header seal eliminating the decel pop. Some just richened fuel screw, it stopped popping, but exhaust valves were still getting outside air. 

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Popping can be caused by a few different things.  One is being lean, another is an air leak in the header area, and some exhausts will pop no matter what you do.  The stock EXC has a fresh air port that puts fresh air into the header for emissions reasons, and just like an air leak that can also contribute to popping.  If you think you're lean there are a few ways to fix it.  On that year for a mostly stock motor a TPS adjustment works well and would be the least expensive option.  A piggy back tuner would cost a good bit more but give you more adjustment options.  A full ECU like a vortex would give you the most control but also cost you the most cash.  Or if you're happy with how it runs, keep riding it as is.  :ride: 

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