I went looking for the infamous 'EPA plug', and found that it had already been removed.  It may be hard to see in this photo, but the idle mixture screw actually stands slightly proud of the hole, such that it looks like no plug could ever have been there.  I wondered if this meant that my bike was running scandalously rich, so I counted the turns it took to fully seat the screw.  I expected 4-5 turns, but it was only 1 3/4 turns!  I then backed the screw back out to the original position and went further to 2 full turns out.  This seems to have cleared up the tendency of the bike to die when I close the throttle abruptly.  So, was she actually running a bit lean?  Has anyone seen an idle mixture screw like this before?

As expected, DragBikeMike was right.  That's my idle mixture screw, with the 'cheap rebuild kit' geometry.

I see a PUDA rebuild kit on Amazon for $18.  The idle mixture screw is the long one, but the geometry of the business end looks a LOT better than what I have now.  Would such a kit be worthwhile, or should I pony up and get the real Mikuni kit for $80?

Hi Mike,

Thanks for weighing in on this for me.  I've only owned this bike for a few weeks and the guy I bought it from did say he'd been over the carburetor.

https://shop.mikuni.com/product/mikuni-carburetor-rebuild-kit-for-suzuki-motorcy
cles/

That's the 'real' kit I was referring to.

As for carburetion issues, I have a few:

Sometimes the bike will hang on a high idle. I can get it to settle down if I blip the throttle a few times.  I've checked that the throttle linkage is tight against the throttle stop when this happens, so I don't think the problem is in the cable or anything like that.

When the engine is cold, there's a tendency to surge or stutter at medium RPMs.  This seems to go away when the engine is nice and warm

The engine sometimes just dies when I roll off the throttle.  If I'm coming up to a stop sign or something and I roll off the throttle abruptly, the RPMs drop and the bike sometimes just stalls.  Backing the fuel mixture screw off a bit seems to be improving this.

I'm going to order the PUDA kit and swap out the junk idle mixture screw for the PUDA screw right away.  Then, when the weather cools off a bit, I'll make time to rebuild the carb with the rest of the PUDA parts.  It's been a while since I've rebuilt and tuned a carburetor.  Any advice for a bone-stock 1998 Savage in Orlando?  Any jetting choices I could make that would get my bike running its best in warm, sea-level air?  Should I stick with the #52.5 pilot and bump up to a @150 main jet?  Keep the white spacer or swap in something a bit thinner?

I'll re-read the carb tuning threads, but any advice you have would be much appreciated.

thanks,
David