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Black sooty deposit at end of exhaust.


estell

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I've noticed some clean-looking photos of the exhaust outputs on many FJ09s on this forum. Mine is covered in sooty deposits. Any ideas of the cause?My bike has 5200 miles but have not yet done the throttle body sync. Could that be it? I'll be doing the sync in January.
The only other thing I can think of is the ECU flash that was done at 700 miles. I doubt that is the cause but I can't think of a third option.
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2015 red FJ-09: Cal Sci screen, Sargent seat, ECU flash, slider combo, cruise, Rizoma bars, Matts forks, JRi shock, slipper clutch

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Depending on where you got the flash done, they probably added some fueling to help smooth out the throttle problems. And the result is a little black stuff coming out of your exhaust. It should wash off just fine. It also means you're having fun because usually you don't get that much unless you're a little throttle heavy.
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Hi guys I too have the sooty deposit but no ecu flash... I think it is just a bit of moisture and carbon from the catalytic converter which I'm sure collects a certain amount of moisture all be  from combustion of just a little bit of rain or water that accesses via the exhaust pipe when on the side stand ,it is of no concern and just wipes off.
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  • 1 month later...
Black, sooty deposits are generally indicative of a motor that is running too rich - those are unburned molecules collecting on the exhaust outlet. I bet if you were to either have the ECU fueling remapped, or installed an aftermarket exhaust, you would see that stuff disappear...
-CD-
 
2015 Yamaha FJ-09: RaceTech Gold Valves, RaceTech Rear Spring, Arrow Full Exhaust - black with w/Carbon Fibre endcap, ECU Flash, Lowered 20mm front, 15 mm rear, Denali driving lights, Fenda Extenda, Tail Tidy, Corbin Seat, Madstad 22" Windshield, OEM heated grips, Woodcraft frame sliders, Grip Puppies, BadAss Cover (Large)....
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Black, sooty deposits are generally indicative of a motor that is running too rich - those are unburned molecules collecting on the exhaust outlet. I bet if you were to either have the ECU fueling remapped, or installed an aftermarket exhaust, you would see that stuff disappear...
or not - just like using a choke on a carbed model, the ECU will richen the mixture when the bike is cold leading to sooty deposits for a short period. Every bike I have owned did the same. 
This signature is left blank as the poster writes enough pretentious bollocks as it is.
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