Can anyone explain to me what exactly causes decel popping. Vance & Hines has a setting on their FP3 that lets you get rid of some of the decel popping. They say it does it by dumping more fuel in the cylinder.

I don't understand how/why that works, because I guess I don't understand exactly what causes decel popping. Hoping someone can explain it to me, please.

Thanks in Advance

 

unburned fuel in the exhaust can be ignited when on decel fresh air ( oxygen) is drawn into the exhaust system from a leak in the joints or even drawn up from the tip. With some header designs, air can be drawn up the left side and added to exhaust at the Y pipe or collector.

the efi shouldn;t be adding fuel when deceling like it does when accelerating.

there are many variables- but too much fuel at any time is not good for the machine or for making power.


in a perfect world all the fuel burns inside the combustion chamber...any more than 500 ppm puts you in the same realm as a VW bug
mike

 

So what the FP3 is supposedly doing by dumping more fuel into the chamber when decelerating is bad?

 

If you did a search here or on Google you'd have enough reading for a week on this subject.
It's-been-beat-to-death.

 

Maybe I just thought my supposed friends on the forum could help me understand without confusing myself more with what I've read. If don't want to help me, please don't respond to the thread.

 

Good luck.

 

As mm guitar said, developed pop I sunburned fuel burning in the pipe. If you of a carbureted bike; when you roll off the throttle, the engine is still turning, therefore it's sucking in air on the intake stroke.

 

The Dobeck DFO/TFI does the same thing.asically the added fuel saturates the exhaust charge on decel thereby keeping the minor amount of unburnt fuel in the exhaust from "popping" when it hits the hot exhaust area just outside the port.

 

Here is a doc from the Thundermax support docs that helps explain what causes decel popping and what they do with their software to help deal with it. I don't know anything about your tuner but at least this should give you an idea of what causes the problem. I have the feature turned on my RK and off on my Softail. Every motor and tune is a little different

http://www.thunder-max.com/techdocs/DecelPop1.pdf

 

Probably does not matter to most but one of the reason fuel injected motors last twice as long as the old carb/manual choke systems is they do not dump excess fuel in the cylinder.