Engine head knocks problem

Hi everyone
my bike (1100) starts having some head knocks since summer has arrived.
Here temperatures and humidity are quite high.
knocking is located in the left cyl between 3k and 4k rpm.
I remapped ECU with beetle map (tnx mark!), the bike feel generally better, but at the moment knocks are still here, maybe a little reduced. [You must be registered and logged in to see this image.]

I'm thinking about trying to change main spark plugs (now i'm running with bpr6es which are the original ones) with colder bpr7es, leaving inner sparks (the iridium ones) untouched.
Can be a good idea? Someone has similar experiences?

Thank you in advance.

Has it done this in previous summers? Are you certain it is detonation?

this is the first summer i've the GRiSO.
yes i'm sure, is the typical pinging sound, it come from left cyl while under acceleration between 3 and 4k rpm.

Yesterday i checked the sparks...the black one is from left cyl. They have 7500km.
To me they seem not to be overheated, at least quite lean
[You must be registered and logged in to see this image.]

I doubt it’s a plug issue but first step is to replace all four. No point in going half way.

On the main plugs you may want to change brands. This 1100 G that I built for a friend did the same but it was built to extreme. He went from the NGK to Champion N7YC and it stopped. Just an idea.
Maybe just a sync & reset TPS. Good Luck & listen to Pete!

Thanks guys, i m also not conviced that's a plug-temperature related issue but indeed is a simple and low cost idea.
Btw today i checked original sparks electrodes distance and i found it out of spec. So i cleaned them and re-set to 0.65mm.
I ve read also a (very old)pete's post about incorrect engine temperature reporting by the probe on the right cyl, so i disassembled it and fulfilled the hole with loctite 8104 silicone grease. I bought 7-grade sparks but not tried for now. I ll keep you informed

I would also recommend you check that both headers are tightly bolted to the head. When they start to blow they can hammer every time a pulse of exhaust gas exits the cylinder. This starts happening at peak bmep just when pinking happens and a leaky exhaust can make an engine run lean.

Obviously slacken the clamp before you tap the header pipe back then tighten the 2 exhaust studs.

Went out for a quick ride with oven-like temperatures and no pinging.
We'll see in the next days what will happen.

Tempermental lil talian bitch! Sorry couldn't help myself.

Dear motografando, I would do a propper throttle body balance. Between 3500-3750 k, engine not too hot (80-90C).
I find my Breva to be very sensible to that, When balance is spot on, pinging disappears.

As i wrote in my prev message, tbs were alteady balanced. I dont want to touch'em until the next cleanup

GuzziSteve wrote:

Tempermental lil talian bitch! Sorry couldn't help myself.

I dont understand