Engine making strange new noise

[Halloweenie]

I rode the bike yesterday and it was not making the noise. When I went to ride her today I noticed the noise. She started just fine, but when I cut the choke and the rpm dropped to about 800-900 (normal until it heats up), I heard it. Did I screw up the PMA and it took a month for it to start acting funny? Please tell me that one of the mighty gurus here have an idea and I don't need to rebuild too much. I'm thankful for any advice you can give me.

The bike is stock except for;
UNI single stage pods
Main Jet: 135
Pilot Jet: 45
PAMCO-running Autolite 63's
HHB PMA- still running a good battery
Only 85 miles into an oil change and has excellent compression

 

[Reid]

pull the points cover and kick it, see if the cam is turning.

 

[Halloweenie]

It is turning, and I checked the advance mechanism and it snaps just as it should. The bike will start and run, I just don't want to make something bad, worse. If I kick slowly then it doesn't make that sound.

 

[Reid]

Have you checked the timing chain tension?

 

[Halloweenie]

That was the first thing I checked, a tiny amount of movement <1mm in either direction and it sits flush to the end for the most part.

 

[Reid]

I think its something chain related. I would back it off and reset the tension if it were mine

 

[Halloweenie]

I'll try that first thing tomorrow. I should add that once the bike is idling above, whatever the rpm range it is for the buzz, there is no detectable/additional noise. It does not rise in pitch and sing like a bad bearing.

 

[Halloweenie]

I backed out the cam chain tensioner, and reset it where I like it. This video demonstrates the sound vs. rpm, I hope it helps to clarify something.

 

[blackbetty]

Sounds to me like it's coming from the kickstart mechanism. If it were me I'd drain the oil and check behind the clutch cover.

Do you still have the electric starter in by any chance?

 

[Paulrxs650]

Something centrifugal perhaps catching? Where does it sound like its coming from? Like Blackberty says, kickstart mech? I would ask a friend to kick over and then ascertain where that noise emulates from. Pop of the covers nearest to the problem check it out.

 

[Halloweenie]

Do you still have the electric starter in by any chance?

Yes, I still have the electric starter in place. That was my thinking, that something on either the kickstart mech or the e-start mech is ratcheting due to a weak return spring. I'm leaning e-starter because the kickstart sounds fine, returns quickly, and smoothly. That leaves the e-start, because it never was very reliable, and makes some unpleasant noises when trying to turn over the engine. I never use the thing and was planning to pull it off at my next oil change.

I am 99% sure the sound it is coming from the alternator side, because it gets quieter when I replace the cover, but I could be wrong. Maybe I only noticed the sound now, because with the PMA installed, I can idle at a much lower rpm (800ish if I cut off the choke too soon) without stalling.

Is there any chance I can convince someone with an e-start to run out and give their kickstart a few really fast kicks with their plugs out?

 

[Halloweenie]

Hugh was right on this one, loose hardware in the PMA. Two screws holding the stator had come loose, despite Loktite. I think I under torqued them when I installed the for fear of stripping something. As per Hugh's instructions, I torqued the dickens out of them with more Loktite. Now everything is good to go. Thanks for your help everyone.

 

[KentMoney]

ah, that was what I was just going to mention, to make sure the adaptors, plates, and woodruff key, etc were all in. It sounded like it was rubbing on something in the slower RPMs too