Engine whine / whirr DRZ 400s

[N4teTheGreat]

I noticed a mechanical whine on the last day of a 1800 mile adventure ride (Wyoming BDR) last month. The sound is consistent with the RPM of the engine and is the same whether the bike is in gear or being revved in neutral.

I removed the cam chain tensioner to inspect it and nothing looked off to my untrained eyes but I'm not sure what else it could be. I do have a manual cam chain tensioner that I can try to see if the stock one has somehow failed and is putting too much tension on the chain.

We still had a few days of riding left when the noise started so I've done 600 miles without anything blowing up or the sound getting worse. I'm not sure what else to check and I'm kind of surprised I can't find any other reports of a noise like this when searching the web. Anything jump out at folks that I should be checking? Bike has 8,000 miles on it.

 

[bcj]

Stator magnets falling off?
That's one mode of failure.
Have not xperianced it. Don't know.

 

[N4teTheGreat]

Yeah, seems like it could be the stator bolts, or potentially a failing water pump gear. Guess I'll start with the easy fix and try the manual cam chain tensioner. If the noise persists then I guess I have a project on my hands...

 

[N4teTheGreat]

Welp, the only thing I have done to the bike has been to clean the filter and reset the auto cam chain tensioner. Whatever the case, that seems to have solved my whine and the bike sounds like a sewing machine again, so, good enough.