My manually fed thirsty leaking carbs...

So after lots of pulling apart and reading old threads on here I think I might have this figured out. Maybe...

So they over fill like crazy and so much that it fills my airbox with gas. It runs like crap and pops a lot.

Until now...

I unhooked the vacuum line to petcock and now I ride it by switching petcock to prime when it sounds like it's running out of gas and then to run or reserve when it sounds a little rich and it does decent in between.

My own diagnosis is that I read on here somewhere the floats lose their floating ability over time, and I figure they can't fight the gravity anymore. I know some good adjusting float heights will solve some of my problem but I'm wondering if i'd be better off finding some new ones or some copper ones.

I hope I'm on the right track. Can anyone chime in on this...

I was ready to give up on this bike until I accidentally forgot to hook up that vacuum line. Now I feel like I am so close.

1982 kz 750 4-cylinder

Thanks in advance....

1) Replace the petcock diaphragm

2) I built a simple float height checker out of the tip of a bic 'round stic' pen and a clear gas line.

The gas line plugs into the part where the white pen shaft used to be. The plastic tip conveniently screws into the drain hole on the bottom of the carb.

With the bike level, hold the hose right next to the carb bowl and make sure your float height is good.