Yes, its the vacuum type. I thought I had it yesterday - I measured my fuel levels in the bowls with the clear tube method, it was lining up about halfway on the upper rim of all the float bowls - about 2mm below the seam, so I thought it was good. Took the bike for a ride, filled it up, rode home, there was no peeing out of the overflow tubes; I loved it.
Got up this morning, and saw some fuel in the bowl I had placed under the tubes, just in case, and sure enough my #3 was leaking again! not a lot - but enough to make me think the jet needle wasn't sealing. I shook the bike a little, and some gas flowed out. Now, to be honest, I DID put the old jet needle back in because I thought it might've just been a case of bad float height; the old one didn't look bad; it wasn't dimpled or appear worn, which in turn led me to think it just might've been the float height...I corrected the float height again, put the old needle back in, went for the above ride, and today went out and found it leaking again. I'm an idiot, I know..,
So TODAY I go out, find the fuel in the bowl I put under the overflow tubes, and decided "Fcuk it - put the New one in;" I'm draining the carb bowls, and when I get to #3 and unscrew the drain plug, it just keeps draining...and draining...and draining...! (Found the problem, I think)… I stuff the drain screw back in to stop the flow, then go to take the tank off, and lo and behold the Petcock (vacuum operated, original 1978 Kawasaki petcock) won't stop draining either! That didn't happen before; but Talk about sticking a finger in the dyke...! And a full gas tank is Heavy!
I didn't find any fuel in the valves - it must've drained into the oil by now..(nice)…but anyway, I have the tank off; and its slowly leaking into one of my oil change bowls as we speak, so at least THAT's stopped for now - kind of...
I'm going to go over the carbs again, make sure my fuel levels are correct, and I want to ask if it's worth it to try to refurbish the old petcock, or...? I've read these original petcocks are crap, and I'm starting to believe it. If you have a 1978 KZ650, (A) did you have this problem too, and (B) what did you do to fix it? I can't think of anything else I can do to the carb - it is Spot On as far as measurements go; and I've also read that the petcock repair kits don't really work either! SO what are my options here...? Does anybody have a decent manual (or vacuum) petcock that works? I was also reading that Pingel petcocks are supposed to be totally frickin' Awesome - and they should be for $115 they want for one (!).