Eegore,
I'm going to chime in here to suggest that you are ignoring some valuable advice that a few of the previous responders to your posts have offered. I don't wan't to offend you but I think you need to consider this.
Quote: (An engine rebuild would just be handy as I wouldn't have to worry about it for a few years and I'd know for sure the front pulley shaft is straight)
In my opinion, regardless of what is causing the noise, a 4500 to 5000 dollar engine rebuild on a 22 year old motorcycle that is worth, optimistically and in excellent condition, about a thousand dollars, is not "handy" it is economic insanity.
The MSRP of a brand new 2017, S40 ( what Suzuki now calls the Savage) is $5,799. Excellent condition five to ten year old examples with very low mileage can be found in the two to three thousand dollar range.
I don't know what the used motorcycle market is like where you live, but I suspect it can't be that different from what it is like here in Western New York. Craigslist and even the large motorsports dealers within 50 or so miles of where I live are literally awash in excellent, mechanically sound used motorcycles of all different brands in the 4 to 5 thousand dollar price range.
It's your money, and your motorcycle, and I wouldn't presume to tell you what to do, but before you hand your bike over to the guy who offered to rebuild the motor at least give my comments some consideration.