Anyone have some information on this setting? I have a single pop that occurs in an rpm range of 2500-3000 between shifts. Seems to be when bike fully warmed. Some searches found this setting mentioned which the FP3 has. I have no decel popping, only some gurgles. Have that FP3 decel setting at 2.

 

It may help if you would include model & year of the bike. Make sure that you are completely rolled off the throttle before clutching in.

 

2013 ElectraGlide Classic. Fyi this is always in an upshift senario, usually 2nd to 3rd or 3rd to 4th, and always a single loud pop. Not always mind you. The setting is a multiplier of fuel removed when roll off throttle quickly, like you would do when running up through the gears, so my reading tells me

 

If you roll off very quickly the ECM will not register a decel quick enough to enlean the engine before a pop. Essentially I think either your running rich in some areas and enleanment isn't going to help you unless you start rolling off much slower when you shift.

 

I see from many forums from autos to bikes and bikes with other tuner models, that many are looking for a solution to shift pops. Since this occurs with temperature change (fully warmed) and the setting is also set with temperature change, ive made a change in those cells to increase the value. Higher the number, the leaner it becomes. Seems the theory is to go either direction to upset the afr in the pipe so no longer ignites. Let you know the outcome when the weather changes this week. Again this is only an up shift pop senario, not a deceleration pop when downshifting to a stop.


Original Cells/Modified Cells

 

You didn't say what bike you have or whether it has the stock exhaust or aftermarket. But a few things can be checked regardless. A loose exhaust gasket at the head, or a loose muffler can cause exhaust popping. Having it set rich at idle setting, will allow the fuel mixture to be increased when the throttle is snapped closed between shifts, and it will ignite the fuel in the pipes. Some aftermarket exhaust system are more prone to popping then others if they are not tuned right.,,,

 

When the exhasut is popping between shifts, is the pop during the time the throttle is turned off or back on?

 

When let off to upshift, I get one sharp pop. One and only one and only when fully warm. I know im close on my tune as I get no popping if I say coast up to a stop or jake brake it. I'm getting 45 to 47 mpg too.

 

I'd try advancing the timing on low maps / TPS at the rpms you are chopping the throttle at..

 

Most of the time when I find an immediate pop between shifts is due to poor sealing at the headpipe junction.
High performance (non-tapered) exhaust gaskets are very difficult to get to seal when using a 1 piece headpipe because the heads are not precisely clocked to the header when torqued. That, and the fact quality control for pipes is not very precise for some pipe.
Tapered gaskets, when carefully used, will seal and handle imprecise headpipe to head mounting variables.

By altering the decel enleanment by at least 50% in either direction will give you feedback as how the table affects the between shift pops. Usually these pops are due to lean, not rich conditions.

Let us know what you find.
Bob