1984 kz750 leaking fuel from #1 carb on intake side. Filling crankcase

Long story short. Working on my dad's 84kz750 l4. Been in storage since 86'. Carbs were meticulously cleaned, needles removed, poked, float bowl passages clear, however I'm having an ongoing issue with #1 carb filling my crankcase with fuel. Note this bike is not a driver yet, will be doing a rebuild once I get this issue sorted and know it's running right.

Clear tube method was used to check float height. However looking at my floats visually upside down they are all different heights, not even close to the required 18.6mm. my fuel needle valve springs are pretty sagged so ordered new valve seats and needles. Waiting on that.

Another issue I'm having is the petcock on ON and not prime when removing tank leaks fuel out petcock like it's on Prime but it's not. Petcock o-rings were all changed as well. If I shake the tank seems like the vacuum seal "resets" and shuts off the fuel.

I've done 2 oil changes just trying to get this thing to stop filling the crank. Note it runs great, just leaks out of the intake boot from air box to #1 carb so I know it's filling the case from there. Sorry for the long post.
Any ideas?

Normally fuel would exit via the overflow tube. Some questions...

Do you leave the bike on the side stand? If so then stop, and use the center stand.

Float valves may need cleaning or replacing.

While adjusting the floats you may have inadvertently caused one to touch on the side of the bowl. This will stick it in the open position.

This isn't the first time I've tried correcting the problem so carbs have been in and out a few times. Floats are nowhere near the float bowl walls. Overflow circuit is clear. And carbs do not overflow when using the clear tube method so I'm assuming the needles and seats are doing their job correctly, however new ones are on order. Bike always stays on center stand in heated garage

Okay tried something I haven't done before. Note it's carb #4 and not #1. I checked float level with clear tube method on carb #4 with the peckcock on Prime position and fuel height has got to be a good 12mm over the float bowl gasket lip. Way too high. Not sure why it changed after tuning them all on a center stand but it did. Going to wait for the new needles and seats before tearing apart and checking again.

While you're waiting, have a read of this topic. It's a much easier way to check/set floats.

www.kzrider.com/forum/forum-index/3-carb...n-setting-fuel-level