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I need ya'lls input on my decel popping. I have a '02 Deuce with the stage 1 AC , ECM download, PCIIIusb, and D&D Power Pipe XHP exhaust. The bike was dyno tuned when I added the PCIII and ended up with a respectable gain in HP and TQ. The adjusted A/F ratio is pretty much right on 13 up to about 4500 rpm where it rises to 13.2 then back to 13 at 5000 and back up to 13.2 at 5500 then back to 13 at 6000. The bike runs great, but it has more decel pop now than it did before the PCIII install. Is this the norm with tuning with a PCIII?

Thanks,
Joe
 

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Not necessarily normal but it happens... you have to make it either too lean to ignite in the pipes or too rich to ignite. Rich is better. try adding some fuel at zero and 2 percent throttle from 1500 rpm and up. I think it's better to throw some fuel at it rather than changing the timing.
 

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SYCLONE said:
Not necessarily normal but it happens... you have to make it either too lean to ignite in the pipes or too rich to ignite. Rich is better. try adding some fuel at zero and 2 percent throttle from 1500 rpm and up. I think it's better to throw some fuel at it rather than changing the timing.
SYCLONE:

Good advice!

:cheers:
 

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to throw something in------reversion can occur in the pipes, allowing cold fresh air to run up the piipe and helping a rich mixture ignite. it may be what is happening.the sound is different than a LEAN misfire on decel. a lean pop will be spat spat, a rich pop will sound like rumble, pop, rumble, pop.if this is the case, late timing may be the culprit. or hot pipes with a rich mix, and the fresh air causes the explosion, much how a diesel works.richening even more may cool the pipes to the point that it doesnt occur, or advancing the tming may actually help burn the leftover fuel before it collects in the pipe. crossover pipes work great also.
 
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