authenticnovelty
XS650 Enthusiast
Hi Everyone,
In the last month or two my bike started making this whining noise. I've changed out a number of parts recently while restoring the bike, specifically the clutch plates/springs. I have tightened and loosened the timing chain and adjusted the ignition timing to match since this sound has appeared. Have also cleaned and greased the cam shaft between the points and timing advance unit. So far no adjustments have made an impact.
The noise begins when the engine starts and ends when the engine stops, in gear or in neutral, same intensity throughout. It changes pitch with the speed of the engine. It's a very smooth noise, almost like an electric motor. I feel like I've heard similar noises come from modern fuel injected cars, like perhaps an alternator whine? I honestly initially thought it may be related to the charging system. My existing wet battery had sulfated and was having trouble holding a charge at the time. I've since replaced the battery for a new AGM and have followed the multimeter diagnostics for the charging and ignition system from the Clymer/Yamaha Manual, replacing the brushes, regulator and rectifier shortly after the battery. I have not disassembled the rotor/stator or looked closely at that area yet, but the resistance for the rotor appears within spec.
The sound has not appeared to impact performance of the engine. Planning to pick up a mechanics stethoscope this week and listen around to see if I can narrow down to an area of the engine.
I've seen number of posts inquiring about odd engine sounds. Not much luck in finding similar with audio samples or solutions on the forums yet. I've attached a video of the whining noise my '78 is making below for reference.
Any suggestions are greatly appreciated. Thanks in advance!
In the last month or two my bike started making this whining noise. I've changed out a number of parts recently while restoring the bike, specifically the clutch plates/springs. I have tightened and loosened the timing chain and adjusted the ignition timing to match since this sound has appeared. Have also cleaned and greased the cam shaft between the points and timing advance unit. So far no adjustments have made an impact.
The noise begins when the engine starts and ends when the engine stops, in gear or in neutral, same intensity throughout. It changes pitch with the speed of the engine. It's a very smooth noise, almost like an electric motor. I feel like I've heard similar noises come from modern fuel injected cars, like perhaps an alternator whine? I honestly initially thought it may be related to the charging system. My existing wet battery had sulfated and was having trouble holding a charge at the time. I've since replaced the battery for a new AGM and have followed the multimeter diagnostics for the charging and ignition system from the Clymer/Yamaha Manual, replacing the brushes, regulator and rectifier shortly after the battery. I have not disassembled the rotor/stator or looked closely at that area yet, but the resistance for the rotor appears within spec.
The sound has not appeared to impact performance of the engine. Planning to pick up a mechanics stethoscope this week and listen around to see if I can narrow down to an area of the engine.
I've seen number of posts inquiring about odd engine sounds. Not much luck in finding similar with audio samples or solutions on the forums yet. I've attached a video of the whining noise my '78 is making below for reference.
Any suggestions are greatly appreciated. Thanks in advance!
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