So, I just recently took my front sprocket cover off to Clean the front sprocket/Chain and lubricate it. After putting everything back together I noticed this noise while engaging/disengaging the clutch. It seems to be a bit louder when the bike is running. I did lose a washer from the front of the gas tank but I have a hard time believing this sound is coming from that. My clutch still feel solid and there is no slippage etc. My fluid is also super clean in the reservoir which makes me think this is something outside of that area ? I can't seem to pinpoint where the noise is coming from ? I've posted two videos on youtube of the noise with links below. It sounds like popcorn popping and also sounds a lot louder in the video than it really is. Anyone have a idea what this might be and a remedy ? Any help would be much appreciated. The Better of the two is first. https://youtu.be/3-wAgiTkG54 https://youtu.be/NNU_iltyTZ8
Funny, by the title I expected the sound to be at the engine. But it appears to come from up at the top, by the bars. I'd be careful not to get gas fumes near.... My initial reaction is that it is coming from the electrical switch for the clutch. You know, the one which controls whether or not the bike can start or not? (Clutch lever must be pulled before the starter can be energized.....) I really would be surprised to find that there is enough power there to arc electrical current, but something is weird with that switch, I think.
This sound is the electric solenoid that activates the flapper valve on the airbox opening and closing with the clutch switch. The buzzing sound on releasing the lever is caused by a dirty clutch switch, try hitting that with some contact cleaner. Aside from working the solenoid a bit harder than usual, this is harmless. The ECU closes the flapper below 5500 rpm in gear, but opens it when the clutch lever is pulled in. Don't ask me why the lever position should change the flapper, but it does. If you have the engine running, you can see the flapper operating as the lever is pulled, but you'll either need to be in gear, or pull the neutral switch wire so the ECU thinks you're in gear.