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Hi,

I got explosions sound out of the exhausts when rolling off the throttle and the rpm goes down from 5k to idle. Is this backfiring? If not what can it be...mixture too rich?
 
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Discussion Starter #2
opposite.
backfiring coming off the throttle's lean. backfiring getting on the throttle's rich.
i'd suggest pulling your plugs to confirm. if they're really dark, you're rich. if they're white/ashy looking, you're lean. if they're tan-ish, you're ok.
 
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well I just installed new NGK so...I guess I'll have to wait a bit

lean? damn, I already remapped by +20 from the original map...what the heck?! weird
 

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I'm not a Ducati technician, but on an i.e., unless I'm mistaken, it's supposed to cut the fuel off entirely on overrun (while engine braking, between shifts, etc). At least, this is how it works on every EFI car I've ever dealt with. I know on my '02 750, if I'm engine braking down a long hill or whatever, I can hit the kill switch and the sound of the engine doesn't change at all, which tells me that this IS what's happening there. So assuming that I'm right about the fuel-cutoff thing (someone who knows Ducs better, please feel free to chime in), I'd also consider the following possibilities:

1) The TPS is misadjusted, and it's not getting a throttle-completely-shut signal while it's revving down.
2) The fuel is shutting off, but you're sucking enough oil past the valve guides that that oil vapor is combusting in the pipes and making the noise.

#1 wouldn't surprise me at all; #2 would be a pretty big surprise on so new a bike, and if your guides were leaking that bad, you'd be worried about the high oil consumption and visible clouds of smoke too.

M.
 
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Discussion Starter #5
well TPS has been adjusted via the pc software and I see no smoke coming out.

Now I had the same problem before I did ANY mods but it was rather minor symptoms.

Something else:

When I slowly twist the throttle up to 2k or so in neutral or 1st gear the air inlet clapets automatically close and open erratically and that's when it start to hiccups all over the place.

So I'm concerned my problem is not really mixture related but rather lies in the Inlet Dict and may be mechanical, no!?
 

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Is popping when coming off the throttle normal? I don't get loud backfiring per se, but there's definately some popping going on.
 
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Discussion Starter #7
popping sound like detonation out of the exhaust pipes!

when rolling off the throttle, gearing down from 3rd to 2nd or 2nd to 1st and let the rpm drop from wherever it is to idle.
 
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