Holy sweat stains Batman!

[Aitch]

It's been beastly hot and my air conditioned truck is getting new binders so I'm riding the bike. Been so hot in fact that for the first time, I'm riding without my full face helmet.
Among other things you notice when riding without a helmet are the noises the bike produces, how clunky the shifts are.
I started hearing pinging noises, at first I thought my front Pirelli was throwing chat against the exhaust but it became too regular for me to buy that explanation. A puzzle... does this happen all the time and I'm just now hearing it because I'm without my helmet? It's a tinny ping, not regular or rhythmic. Sort of sounds like metal popping when it heats up.
I then recalled the last time I filled up with gas. I apparently got distracted by the view at the next station island and punched the 87 octane button instead of 91.
Today, I was only about 90 miles into my 87 octane fill-up, but topped off with 91 octane on the way home from work.......I think the pinging has stopped.
Anyone have a similar experience with low octane fuel, or should I look elsewhere?
It's been quite a while since I've been on, so I hope all are well and enjoying their rides.
Aitch

[owldaddy]

Anyone have a similar experience with low octane fuel, or should I look elsewhere?

Yep, most of us have had that problem. The lean running of this engine requires higher octane fuel when it is hot. I think you can get away with 89 octane when the weather is cool. When it is hot, you better go for the 91 octane. I have increased the fuel mix of my mixture and still need to run 89 octane when it is hot.

[boxermania]

owldaddy is correct, assuming the engine is in a proper state of tune.

The different formulations by brand/location also play a role, but the primary source is lugging the engine, easily accomplished by the gobs of torque down low that the boxer has.