Engine noise, possibly from camshafts

[gearhead13]

At times, when I come to a stop with engine at idle I have a rattle or something I dont know how audible it is, but I can feel it thru the handlebars. The vibration doesnt seem to be at the speed of the engine, but lower frequency. Maybe camshaft. I remember my last valve lash work done. I was checking the tightness of the caps over the cams, and on the right side of the engine, half of the bolts on one cap were stripped. It scared me so I never checked the left side caps.
So, maybe my noise/rattle is from this source maybe... And maybe some of the lefft side are stripped as well or worse.
I am going to take the valve cover off again and check ALL the bolts, maybe pull the caps as well to see the bearing surfaces of the cams.
Should I helicoil the stripped bolts or can I drill oversize?
Are the bosses where these bolts go into open at the bottom or closed? I am worried about shavings getting into the engine
TIA
Richard

[Nessism]

What did you do about the stripped cam caps last time around? If you did not repair them the head may be toast now.

[gearhead13]

What did you do about the stripped cam caps last time around? If you did not repair them the head may be toast now.

Ummm, nothing. From what I suspected, its been like that for maybe thousands of miles.
Here is some sound video I made of the engine running. Might need Quicktime:

http://www.bestpcman.net/uploads/Picture.MOV

[Guest]

Heli-coil them. Easy job. Use grease on the tap to catch the metal shrapnel.

[Nessism]

Yea, not a hard job but you need to pull the head first. When drilling the head use a drill press also so you make sure the holes are going in at 90 degrees.

Hope this helps.