Last night I took the carbs off my 1983 KZ550 (I just bought this bike a month ago) to clean them and found something surprising- the main jets on the middle two carbs were unscrewed fully (just sitting there loose on their seats) and the main jets on the outside two were screwed in fully. I cleaned everything, screwed all four jets down to hand-tight, and put the carbs back on the bike. I started the bike and it seems like my warm up time has greatly decreased, but now it runs very rich - it idles around 4K and I have the idle screw fully out. I also hear gas exploding in the exhaust. How tight are the main jets supposed to be? I'm tempted to just put them back how I found them but it didn't look right... My book doesn't give a good explanation but the picture looks like they should all be screwed in fully. How can I adjust the gas/air mixture to make the bike run more lean? Thanks!