2020 FLHX 107 with 12,000 miles. Bought new by me. Stock bike. I run Exxon 93 premium. I’ve also tried Lucas motorcycle octane booster that’s supposed to boost octane 3 points. No impact.

This M8 has had a consistent pinging under harder acceleration since new. Not hard knocking, almost sounds like a rattle, but only occurs under harder acceleration. Doesn’t really matter what RPM or what gear. If I roll into it good, not WOT necessarily (but also at WOT), it pings/rattles extremely consistently. Not loud. But can definitely hear it, especially with stock exhaust. Hot weather, cold weather, after riding the bike an hour, or after warming it good from a cold start and riding five miles. Doesn’t matter. This pinging is not present whatsoever under normal cruising, until I decide to accelerate harder than usual. I’m a pretty docile driver otherwise. Ride solo. I weigh 220, so the bike is not loaded.

I loaded a Fuel Moto Powervision stock improved tune and ran a couple of tanks of gas through the bike at their behest. No change. I ran a couple of Powervision "Autotune basic” twenty minute sessions. No change.

I saw an Oct 1, 2021 bulletin on Dynojet's website “Addressing Spark Knock or Pinging”. Read it and followed the instructions for a “Quick Tune”. I increased fuel by 5 and retarded spark by -3. No change. I then increased fuel another 5 to 10, and retarded spark further to -6. No change. I reset to 0 and 0 on fuel and spark, which means I should be running my dialed-in stock improved tune from Fuel Moto.

My next step would be to send a couple of twenty minute datalogs to Fuel Moto (which I have not run yet), but I am wondering if this is a tune issue, or something else.

Advice most welcome.

For what it’s worth, I’ve search here, and the rest of the intertoob far and wide going back five years since the M8 came out, and have found instances identical to mine. The only ones resolved were with Fuel Moto and Powervision tunes, but no details to indicate that much attention was required. I described to Fuel Moto what my issue was when I ordered my Powervision.

 

Have the same problem with a 114. I put a de catted header pipe, opened up the air cleaner, and a Power vision from Fuel Moto with there tune. Worked good for about 6 mo. then a low ping on acieration. Called Fuel Moto they said to re tune it being computer illtreated I am going to take it to my Dyno tuner to have it tuned..

 

To the OP, i don`t have an answer but I`d like to thank you for providing a detailed readable description of the problem

 

Please send us several 20+ minute logs with your Power Vision thru the Fuel Map link on our website, if it is a tune or spark related issue we will be able to identify and resolve it.

 

Thanks. Will do.

 

Heat shield rattle??

 

I see FM has already entered the thread with advice. I was going to suggest datalogging to prove that it is in fact spark knock. It's pretty obvious when you look at it in the DynoJet software.

 

I know you said you use a Top Tier, premium fuel, but I get the same thing when I use "cheaper" fuel. When on a steady diet of Shell 93 octane, I don't hear it. I have a "canned" FP3 tune to match my V&H Eliminator slip-ons. My 2018 114 Heritage did it when stock, too. It's pretty rare so I live with it.

It's great that FuelMoto responded so quickly. Hopefully, they can solve it.

 

more like a bag of wrenches

 

Logs sent. I expect it will be a few days. Will report back what I learn.