Backfiring 82 KZ1100. Won't start.

only cleaned them, and they where already clean from last fall. I'm waiting for larger main and pilot jets for Z1E.
no idea what the thumb test is, ill check it out on google.
but do i feel stupid, went in the garage last night and realized that there was not more fuel left in the tank with all those emptying carbs bowls and tests. havent had a chance to try to start it, will try tonight.

ah, thumb test is for compression. I have a compression tester. my compression is #1: 155, #2: 150 #3: 150 #4: 155
so the compression is more than good. and the numbers didn't change since last fall before I dissembled everything.

No, you lift the slides with your finger, put your thumb over the large vent on the top beck of the carb, let the slide go and see if it stays or falls quickly. I was thinking if the diaphragms are shot, it might do it.
Steve

I know they cost a lot but the bike won't run with bad ones.
Steve

My $0.02. Invariably the symptoms you state popping, flames and backfire through carb is almost always a severe intake leak. Perhaps you have pinched a hole in your new rubber tubes. Also if you do not have a the carbe bank mounted fully (I know form exp) massive air leaks occur and do what yours does. . Secondarily I go with torn or mismounted diaphragms next. This also causes air leaks and more of the popping decel poor performance variety issues. You are not far off it's something obvious, but insidious :evil:

R

thanks guys, I found the problem. I switched the ignitor / timing advancer with the one on my part bike and all is back to normal.