I have developed a new rattle - when I disengage the clutch when accelerating, it sounds like a sewing machine running wild.   I did change the headlight bulb, and thought it might be that, but the rattle seems pretty specific - when the load is removed from the motor.  In addition, it really runs better with the choke half open, just opening it up feels like I twisted the throttle a 1/4 turn.  I have run half a can of sea foam through it, and added the rest to a fill up today.

Is my motor about to blow up?

Background:
It is a 2001 Savage with 2500 miles.  I have put 500 miles on it in the last month or so, before that it sat for most of 4 years, had 2004 tags on it when I bought it.  I changed the oil and plug soon after I got it and I recall the plug was fouled and seemed to have some gas on it.  The exhaust is after market, about a 22 inch fishtail.  I have the OEM exhaust and have thought about putting it back on, but I am afraid I will introduce new issues with leaks etc.  I hope to get it into the dealer for a carb cleaning next week; I have thought about trying that myself, with Clymers in hand, but since I have never heard one of these running "right" I am not sure I am ready to handle that either.  I am not averse to wrenching on it myself, but manual dexterity is not my strong point, I tend to drop small pieces, often.

any advise?

what is a fair price to pay to have the carb cleaned?

Sorry, never paid anyone to work on my bike.

Dropping small parts is not a problem, just make sure you're ready for it.  Big clean table to work on, clean bare floor beneath.  Savage Wahine wrote up that great carb cleaning post just for you.  I'd advise you to do it before you find out why we call her Savage.

So what's she doin'? popping, kaboomers, cutting out?

If you don't do it yourself, make sure to ask what jets are in it.

Been sitting for awhile?  do yourself a favor, replace the gas line and vac line.

Well I am happy but embarrassed to say I found the rattle, a combination of the headlight and a repositioned fork bag with tools.  Riding without the without the helmet really helped pinpoint it and I have resolved that.  

I still have the hesitation and popping with the choke closed. The popping is not terrible and I kinda like it and the pop when I shut her off.  The hesitation is a problem.   I will try replacing the lines this weekend, and burn the last of the seafoam laced gas.  Perhaps when she is empty I will try to remove the tank and petcock and see what I find.  

Will read Savage Wahine's posts about cleaning the carb and choke, but I will need to order a jet kit before I pull the carb out.

thanks for the replies.