top end noise

yep, they all make that noise, kinda sounds like you can hear the reeds opening and closing, anything louder will require a look inside
 
yes i think they are a little loud but its hard to say if yours has a problem or not. how about a vid of it running i think we should be able to tell.
 
Youtube dude! Then post a link

By the way. I had the same concern when I bought my first one a few weeks ago. It's the nature of the beast;)
 
Blaster's chattering noise is typical. It's usually just the reed petals opening and closing, but it's a very distinctive chatter. It's best to imagine what the reeds SHOULD sound like when they open and close fast and if it sounds like it, then that's probably what it is. Anything NOTICEABLY loud and abnormal is rod bearing, piston slap, pinging, crank bearing failure.