I just joined and was told by fellow members to post here (I hope I am not violating the protocols).

BLUF:
I pulled the EPA plug out of my carb and the pilot screw does nothing.

Background:
I found a 2001 Savage which was purchased new by an older gentleman and promptly parked in a barn.  714 miles.  It is immaculate.  

Details:
I changed the oil, spark plug, air filter, and gas because the bike hasn't been ridden in almost 20 years. I also took the carb off and broke it down (three times now) and used carb and choke cleaner and my air compressor to try to clean the circuits.  It runs.  When idling, the bike indicates (to my weekend warrior motorcycle mechanic mind) that it is too rich.  Black smoke, gassy smelling exhaust, and the plug is fouled quickly.  After enough idling the bike ceases to run and I have to clean the plug.  I pulled out the EPA plug to get to the pilot screw.  I was thrilled until I screwed the pilot screw all the way in and nothing changed.  My understanding is that when the pilot screw is all the way in, fuel should be cutoff, like my other motorcycles. The bike keeps running rich.  Whether all the way in or turned out 1 1/2 times (recommended) there is no change in the idle or the signs indicating it is too rich.  I took the o-ring, washer and spring off and screwed it back in to see if would seat better.  Nothing.  The bike seems to run fine at the mid-range and full throttle when the needle and main jets are actuated (as I understand carburetors).   I was at my local Suzuki shop today and the mechanic unfortunately had no recommendations for solving this other than cleaning the carb (again!).  I can't find help online for this either.  I appreciate any insights because I want this awesome bike to run optimally.  Thanks!

Batman,
  Thanks for the prompt response!  As far as I know, and the seller told me, everything on the bike is factory. This is my first adventure into Mikuni vacuum carbs and I am learning.  I live in Pennsylvania which requires a state safety inspection.  I just bought the bike and I have an appointment tomorrow morning to get it inspected so it is street legal.  My plan is to get it to pass and really dig in, so I am not going to break it down tonight even though it is running sub-optimally at idle.  What do you think is the best way forward when I get it back?

Justin,
 I appreciate the response.  I'm just figuring this bike out so here is what I have done:

I have the idle screw cranked down all the way in order to bring the RPMs up at idle.  I have read that people like to turn it down to sound like a Harley (which it isn't).  I don't have a tachometer but it doesn't sound obnoxious.  Unfortunately, I can't go screaming around the neighborhood until after tomorrow afternoon because of PA State inspection laws.  Are you suggesting I grab a screw driver and mess around with it until I get a decent tune on the carb?  I am looking for any experienced advice as I move forward.

v/r

Matt

See the black rubber disc in the end of the plunger.  Make sure it is in good condition.  Make sure the plunger is clean and smooth.  It must move freely in the bore and make good contact with the seat in the bottom of the bore.

DragBikeMike wrote on 06/04/20 at 23:35:00:

Make sure your petcock diaphragm isn't rotted out.  If the diaphragm has a hole in it, fuel will leak down the vacuum hose and directly into your intake manifold.  That would be the vacuum hose that connects to this hose nipple on the right side of the carb (just below your mixture screw).

I think we have a winner.

This is a fairly simple test. The petcock shouldn’t flow fuel with the engine off. If fuel flows from the fuel line, the petcock has failed.  The fuel you are smelling is probably coming from the breather vent because fuel has leaked into your oil. Remove the oil fill cap and see if the oil smells like fuel.

If the petcock has failed, a replacement petcock from a Yamaha Raptor has proven to be a bette replacement.

Alright Fellas,
 I followed your recommendations.  The fuel enrichment circuit is good.  I drove 50 miles one way to the nearest Yamaha dealership that had a petcock in stock and picked up an OEM one.  I put it on, covered the vacuum on the carb, and the bike started fine.  The pilot screw still does nothing when adjusted or turned all the way in.  Is this normal?  
    Additionally, EVERY TIME I turn off the bike, there is a one second pause than an enormous backfire.  My wife is getting pissed every time I do it which is kind of funny.  I have not taken it on the road yet because I don't want to have to reassemble then disassemble again if it is something I can fix now.  Thanks!

Modification to my earlier post:

I get tunnel vision sometimes.  My wife said to me "Isn't it idling really high?"  I had jacked the idle screw all the way down in order for it to run.  I adjusted until it sounded close to correct and this has diminished the backfire.  Now I get a mild puff.  I think it is time to put it together and hit the road.  I'll report on the consequences.  Thanks again!

v/r
Matt

A mild puff is normal. Pull the choke right before hitting the kill switch if it bothers you or your wife.  As JOG pointed out idle speed is a little high compared to a HD at 1100 rpm but don't go lower or you'll starve you camshaft of oil.

Gentlemen,
 It's running like a dream!  I just had it out on the road and no issues.  It was the petcock the entire time.  I want to extend my sincere gratitude to all you for your expertise and generosity with your information.  I got a helluva bike with only 700 miles on it and am happy the summer is here.  Thanks again for everything.

v/r

Matt