Anyone knows what this sound is - detonation?

Sullybiker · 02-22-2017, 12:39 PM

You can hear it in the video as I apply throttle out of the corner: (advance the video to 12:50)
It sounds like a vibration / rattle. It's not hugely intrusive, but it's one of those things as a rider you notice. I thought it was the muffler end cap (it loosens as the muffler heats up, and vibrates) but I'm certain I only hear this noise under load.

My bike's done this from day one, irrespective of ambient temperature. I did think it was just the bike's character, but since looking into carb tuning and watching a lot of videos on the subject, I've wondered if it's spark knock / detonation. It happens in any gear, often in the same rpm range (hence it may be mechanical) I do run 87 octane (I usually don't bother with premium unless the manual specifies it) and will try a higher octane fuel next tank.

Bike runs great, very smooth, I'm just fearful of detonation if that's what it is.

02-22-2017, 12:39 PM	#1
Sullybiker Join Date: Dec 2016 Location: Western PA Posts: 363	Anyone knows what this sound is - detonation? You can hear it in the video as I apply throttle out of the corner: (advance the video to 12:50) It sounds like a vibration / rattle. It's not hugely intrusive, but it's one of those things as a rider you notice. I thought it was the muffler end cap (it loosens as the muffler heats up, and vibrates) but I'm certain I only hear this noise under load. My bike's done this from day one, irrespective of ambient temperature. I did think it was just the bike's character, but since looking into carb tuning and watching a lot of videos on the subject, I've wondered if it's spark knock / detonation. It happens in any gear, often in the same rpm range (hence it may be mechanical) I do run 87 octane (I usually don't bother with premium unless the manual specifies it) and will try a higher octane fuel next tank. Bike runs great, very smooth, I'm just fearful of detonation if that's what it is.
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