need help kz 750 csr twin 1982 ventiltion

hello,I just joined this kzr and I have some questions.
I have built a bobber and i need some help on the ventilation.Again its a kz750 twin csr 1982

1.dose the gas tank have 2 petcocks are they vacuum pet cocks?

2.on the carbs "mikuni carbs" I have a plastic Tee and a metal Tee connecting the carbs.The metal Tee
has the fuel line attached to it but the plastic tee? well i assume its for ventilation,it is plastic.
but dose it need to be capped or what?

3.the bike runs like crap. On choke it has more power ?

4.what are the specs on fuel air. its at 3 turns out as of now.

I dont know much about the csr, but i have 76 kz750 twin... I think the carbs may be different but it sounds like your running lean.

If when you put the choke on it runs better it means its running better with more fuel to air. 3 turns out is a start... check the plugs and if they are white back the mixture screws out a little at a time until the plug turns tan... if they turn black you went too far. Dont turn out past 4-4.5 turns or the screw wont do its job..... if you cant get it richer with the screw you need bigger jets...

Is it running pods and free flowing exhaust? If so you may have the same problem as me. My bike has the Mikuni bs38s and getting bigger jets is harder and harder. Im running a bigger set of pilots and the main jet I had to machine out bigger, and it still runs like crap. I can get the mixture pretty nice at idle and low rpm, but when it opens the main jets its running lean (highway speeds)

Im getting ready to swap over to some Mikuni VM 34 roundslides. Making a custom set of carb boots and seeing if i can get it running better. Those carbs are much easier to synch/tune.... jets are readily available..

Only one petcock and yes it's vacuum operated. It feeds the topmost tee fitting. The lower one is the overflow for the bowls. You can run it up towards the battery then down like the factory did or just run it straight down behind the engine.

Great source of twinnie information including the factory service manual download here.

www.armbell.com/forum/index.php?mforum=kz400

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