05 450 exc bottom end noise?

Hi all. Just put a 540 kit on my exc and had a valve job done. When i was picking my head up from my mechanic he was saying something about a nut on the crank that can sometimes back off and cause some bottom end "rattle". Now maybe that just got me a little paranoid, or maybe its because i haven't heard the bike run in like 8 months but i seem to notice a little noise that doesn't completely go away when you pull the clutch in. Now is this very common? Or something ti be concerned with, or am i thinking too far into it? He said you can somewhat check to see if that nut is loose by looking in the oil filter housing(s). Can anyone confirm this? Or had a similar issue? Thanks in advance.

He was talking about the crank nut on the clutch side. I doubt it came loose sitting idle, so you are paranoid or your rod bearing is going. More paranoid now? lol. You've just forgotten they sound like chaf cutters. To test if the crank nut is loose, hold your brakes on and let the clutch out to load the motor right up. IIRC, doing this when its loose will quieten it down.

If you have access to a boroscope, take the oil filler cap off run the scope down and you can see the nut. Did this to mine when I first got the bike, I was coming off an XR 400 so it sounded "Chaf Cutters!"

I don't even notice the noises now.

Well i pulled the clutch cover today. And everything looked good. I think i may have been just over thinking it, because the more i hear it run the more it sounds normal. The only thing i did find was that roller bearing the rides inside one of the gears for the electric starter was laying under the clutch cover, but Im pretty sure it just fell off the shaft when i pulled the cover. I couldn't see that thing just flopping around in there without being mangled :lol: so i think everything is a-ok! A little peace of mind for myself anyway.



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