I'm new to tuning and have a lot to learn, but trying to tackle a little at a time. I'm currently trying to understand the knock retard events in my PowerVision log.

Is the goal to achieve zero knock events?
Are they bad for the engine?
How many events or how large a retard value is bad if I can't tune it all out? I'm getting mostly .5 to 1.5, with an occasional 2.0, in values.
When I see these events in the log, is the system retarding the timing and the value is how much is being retarded?

Here is the scenario. I added a PowerVision tuner to my stage 1 2018 Fat Bob. I initially ran the custom map from FuelMoto and it ran fine. I took a look at the logs and there were a lot of knock retard events on both cylinders, so I decided to run some autotune sessions. After 2 autotune runs, the knock retard events have subsided, none on the front and only some knock events on the rear cylinder when I crank on the throttle and the MAP pressures get in the higher range.

Can anyone enlighten me on this area of tuning?

 

Unless you go a rather conservative route with ignition advance you'll likely encounter knock events every now and again. You are correct with the amount shown in the log being degrees pulled for the knock event. If you want to further reduce the occurrence go into your rear spark table and locate the cell where the timing was pulled. Since it's during a throttle transition I would go back up a few lines on the log and also locate the cells that would have been immediately before the line that shows the timing retard. Take out 1 degree timing in these cells and go for a ride/make another log. Some other things that can help are adding acceleration enrichment (this impacts both front and rear though) or possibly raising the VE for the rear cylinder in the cells where the knock occurred. (maybe these cells didn't get any hits during autotune and are slighly low?) There are quite a few ways to skin this proverbial cat and I hope this helps.

 

what he said... pull a little timing, add a little fuel where it happens.
if newer bike there is also iat en et retard tables to consider

 

From your description, you are fine. The numbers are timing being pulled. Your reduction of events after autotuning shows it was fuel related. A little reported knock here and there is nothing. Sounds like you could run autotune again and/or slightly richen it up in the load area you are seeing it in.

 

Also helps to know when the bike is retarding timing. Is it after you leave sitting at a stop sign? Maybe address it in IAT timing tables. Does it retard when fully warmed up to 260f but not at 220f? Maybe address engine temp spark tables. But I would get fuel straightened out first and check gaps on the plugs, wires and good connections first.

 

oh yes, that's important... make sure the plug is good and the gap is right. I used to have a ton of retard events on my front cylinder only, running the exact same timing on both. pulled the plug, cleaned, regapped (it was a bit wide) and knock evts are gone.