Thanks everyone for the great recommendations. By the way -- yesterday I had loosened and removed the clamps from the back of the carb where the rubber airbox boots connect so the carbs could get extra air, I did that because yesterday the plugs were fouled with gas. Now that didn't change anything, loosening the rubber airbox boots at the carbs. But the carbs are flowing lots of air.
I've never used SeaFoam for the gas tank so I bought a can -- I put 2 ounces in 1 gallon of gas which is twice the recommended mixture and sloshed the tank around.
I started it as usual with the choke on and let her run on the choke for awhile (5 minutes) then switched her off and cut some weeds out of my front hedgerow for 25 minute.
Came back to the bike and started her up -- no change, I have to start the bike with the choke on and as soon as I try to rev it, the engine dies, and likewise if I try to turn the choke off it dies (and I have checked that the idle adjust is set OK).
So I put 2 more ounces of Sea Foam in the tank and sloshed it around, and started it up on the choke and let it run (it runs around 1200 to 1500 rpm on the choke) this time for 10 minutes. I wanted the Sea Foam to work into the carbs.
At the end of the 10 minutes all of a sudden the RPMs suddenly started to climb!
Good ole' Sea Foam apparently!
So the revs kept climbing and I went to the bike and NOW she responds correctly to the throttle -- when I open the throttle she revs UP and doesn't die!
Okay so after 5 minutes of "could this be true, lets try revving it again, yep it still revs!" joyfulness I got bold and started to take the choke off -- the motor stayed running!
So finally after 4x the recommended Sea Foam concentration the bike's revving at idle with NO CHOKE ON. Now the rubber airbox boots are still loose so the motor's pulling lots of air still.
I drove the bike around the block tears in his eyes I guess
with the choke off at least at the beginning. To keep it running around the block sometimes I had to turn the choke on though.
Only running on 1 cylinder consistently.
Back home I pulled the spark plugs.
The front plugs are still fouled with gas. The rear plugs look great -- dry and tan-colored.
So I put the clamps back on to attach the rubber airbox boots to the carbs.
I started her up -- now with less air getting into the carbs (rubber boots are back on and tight) the bike won't start without the choke and dies if I take the choke off.
Any suggestions? I feel great about the Sea Foam, thanks dudes there is a light at the end of the tunnel