I had a 155 main jet and a 55 pilot jet, but it was running WAY too rich.  I also had 2 #4 washers in there and still had a backfire--no, there are no exhaust leaks.  So I dropped back down to the 52.5 pilot and a 150 main.  Since I'm at about 600 - 800 feet elevation this seems to be the correct setup.  I also shaved the white spacer down to about 1/3 (give or take 1/8) and replaced the washers with it.

Now when I shift into 1st and give it the gas, it dies!  If I mess around with the idle speed and the idle mixture, then it will at least start to move but it feels like someone has replaced my 650 with a little dirt bike.   What in the world have I done now?  Do you think I've shaved too much off the white spacer?  Is that symptomatic of a flooding bowl?

Ahhhhhhhhhhhhh, good news at last.  

Whew, that's a tough question.  No I don't have any pictures of it, but I did see a good picture in the Tech Section ... can't remember which page?  40 mpg is ridiculous!  The fool that I am, I put Lancer's biggest jets in right away.  That made it incredibly rich and it didn't run right at all, but even then I was getting about 50 mpg!  Sounds like your carb is in serious need of some TLC.

I am still experiencing the flooding problem.  Earlier when I reported that removing the bound washer fixed the problem, it did ... but only for a day.  :'(  Since then I've taken it apart twice and still it will not run.  I can feel, and smell, it flooding while I'm trying to start it.  So today I have given up.  I'm putting it in the shop and letting the professionals figure it out.  I've learned a lot and come a long way, but I'm just in over my head on this one.