CX500 GL500 650 Global

I don't wanna write a book but would like to let you know what I've done.

First off I'm working on a Beautiful 1981 Honda CX 500c. My issue are carb related. Pull the choke up runs....almost normal choke down it just sputters and no throttle responce. I have now cleaned the carbs counting today 4 times. I purchased the Mike Nixon clean book. The last time prior to today of having the carbs off was the best the bike ran. It had all the throttle responce back, no choke up required, Pulled up over 9000 rpm no problem, but had an off idle sputter and pop. As you slowly turned the throttle past this spot and would all of a sudden come to life, Almost like a 2 stroke power band. So thats why I pulled them apart again today. I fugured one more good cleaning. (I let them soak in Laq. Thinner today for the first time) When I reassembled and put them back on the bike its right back to the way it was before. Popping and farting. No throttle responce, and if i pull the choke up it runs better. I also put my vacuum gauge on the intake holes to check my carb balance and my vacuum gauge is all over the place. At idle roughly 1100 rpm's my vacuum gauge goes back and forth between Vacuum and PSI on both cylinders at a very very rapid pace, looks like a windshield wiper on steriods. I sprayed starter fluid around seals looking for vacuum leaks but it almost seems like my bike goes back and forth between vacuum and pressure at idle and low rpms. Not until I give it gas will the vacuum needle on my gauge start to slow down and the more gas I give it the steadier the needle on my vacuum gauge gets. I don't wanna believe I have a valve issue because it ran so close to perfect before I took it apart again today. When the boys go to bed tonight I'm going to rip he apart again. Was hoping someone my have some insight before I do. Thanks for any help you might be able to offer.

Check for air leaks on the carb boots.With the bike idling spray some Carb/Brake cleaner or WD40 type aerosol around each of them.If the engine speed changes in any direction there's an air leak?

UPDATE:

Went out that night and tore the carbs apart again. Took some of your tips and tips out of the book. Got them back together and they where much better? Still not 100% For example when i down shift I like to hit the throttle real quick between shifts give it that beautiful sound that bike has and almost every time i hit the throttle it pops. Not loud, sometimes almost like its coming from the carbs and not the exhaust. I have new intakes on both sides, and I have checked for leaks with both propane and starter fluid and the idle doesn't change. But on a good note it really runs good. will idle at 1100 but i can get it to go lower and it will stay running. I have it set at or just above 1100. My battery is weak. The bike starts but you can tell the battery isn't what it should be could this by any chance have any effect on anything? I have been adding carb cleaner to the gas, don't have alot of faith in the stuff but some people swear by it. Put little over 100 miles on it so far. Idle mixture screws.....I have them all over right now. Going to reset them tonight for the ride to work tomorrow to 2 1/2 turns out. What do you suggest?? On the vacuum thing ..do you think it matter that I have a guage that reads both Vacuum and PSI. Its a duel Craftsman gauge to read both positive and negitive pressure. Maybe if I had one that only read vacuum. Thats what i'm going to try next. No matter what there is something about this bike I just "LOVE". I have a very nice V65 magna and I love riding this just as much. Thanks for your help and I'll keep tinkering!

Couple of things affect popping.

Air Cut-off Valves.Here's my old Carb page,

http://www.geocities.com/sheppola/carb/carb5.html

They can be left in and Bypassed by making a circle of rubber and replacing the small O-ring shown on the page but leaving the old ACVs in or of course renewing them.

Any leaks in the exhaust system can cause popping and or backfires.

HTH