Its not a big deal to add some fuel in the decell area but you should make your dyno guy fix it. You paid good money for a complete tune and that is part of tuning. I find if you leave the decell area in closed loop after time adaptive will drive this area leaner and cause this issue.

 

255 cams seem to want to pop even on brand new bikes. Dyno or me tuning it I have never got 100% out. Test riding new CVO bikes I noticed they also pop a little. I imagine if it is really important to a person you could get 100% out but how much fuel do you want to dump to get it all out?

 

This +1

I've never understood why people are so adament about having zero decel pop. Every manual shift vehicle I've ever drove had decel pop (stock or modified) when engine breaking, it really isn't that big of a deal.

To each there own I suppose, it's your bike, take it back if you're not happy but a little decel pop is nothing to be worried about.

 

I didn't need to "dump" any in. I was able to drop it out of closed loop to prevent the AFVs from messing with decel (at 20kPa), and add some timing to insure everything was burned. FWIW, there's no reason at all a 255 cam should inherently have decel pop.

Like I said, it's really not difficult.

 

Take it back and get it fixed. Your bike, have him make it right for you.

 

Why do you want to take it out of closed loop? That just kills fuel economy and makes the bike run dirty. Oh and you have done the same thing as adding fuel to decel, but now it's there all the time.

 

It does nothing of the sort.

I dropped it just below closed loop (so it's at .975 rather than .977). That prevents the AFVs from adjusting the VEs.

 

I have not looked at your map so I don't know exactly what you are doing but the end result is the same, you added fuel in a certain area of the map under a specific load condition. Again how much do you want to add to get rid of the decel pop? BTW, I'm getting 49 MPG.

 

The end result is not the same. If you keep it in closed loop and adjust the VE table, that VE will be modified by the AFVs and change over time. That's the whole point of closed-loop.

 

It actually depends on what kind of pop, and make the 'fix' match the pop.

If it pops right when the throttle is closed? Use DE. Also can do what Train is doing, with a PV.... if the pop isn't fixed by DE alone.

Now... long decel pop is different. Say you rev to 4k and close the throttle, then you get sporatic pop between say 3k to 2k? DE won't fix this. Again, if you use PV or SEPST, take the lowest KPA region and add a little fuel to the AFR range. Take some experimenting. Add a tad bit of timing on top, and should get fixed.

Now... with a TTS, one adjusts long pops totally different. TTS has closed throttle spark. Using that table, jack the 3000 rpm range timing up to like 30-40*. That advanced of timing will suck the flame front back into the pipe. Keep under 1500 rpm matched to the main spark tables. I match 2000 rpms somewhat to match idle.

DE is instantaneous. It is not a fix for pops that occur more than a second or two. Timing and fuel will need to be messed with.

Dirty Air? Once you use any tuner you will be out of EPA compliance anyways, so it becomes how well one wishes the bike to run as configured.

Train, depending upon how well low RPM VEs are fixed, you will STILL have a bit of AFV action, even in open loop, if the VEs are off a bit. To dirty air, how much fuel, when the throttle is closed, do you really think is used on a tenth of a Lambda point? Too small to measure at the exhaust for sure.