Reassembling 750 carbs question

[Kbs]

Hi
Rebuilt my carbs and after reassembly on the bench i noticed the butterflies are in different positions at rest ?  Before i put them back in the bike i would appreciate some input as to whether this is ok or do i need to take it back apart ? 

[mollusc]

This is normal after disassembly.  What you have to do now is a bench sync so that all of the butterflies are in the same positions.  #2 is normally the reference; there should be adjustment screws between each carb so that you can bring them all into alignment.  I usually pick one of the tiny holes in the carb throat and adjust each butterfly so that all of them cover exactly half of each hole at the same time.  Fine tuning is done once the carbs are back on the bike and it is running.
You should also make sure to set your mixture screws to the default settings before putting the carbs back on the bike.  If you're talking about the 1991-2003 CB750, that is 2 5/8 turns out from lightly seated.  (That is, screw them in all the way -- but don't screw them in hard -- and then back them off 2 5/8 turns.)

[Kbs]

THANK YOU !  I did set the mixture to the 2 5/8 turns.  This will help me get her back together.  Thanks again !!

[Kbs]

Well carbs are back in the bike and initial tests look good.  However, as soon as i fired up, the diaphragm at the petcock starting leaking  .  So now to find a rebuild kit and get it torn apart.  At least making some progress. Lol
Thanks again for the help

[Bob H]

...diaphragm at the petcock starting leaking  .  So now to find a rebuild kit and get it torn apart.

I got this complete new / aftermarket petcock 2 years ago and it has worked well. It was CHEAP. Right now it is $18
https://www.amazon.com/gp/product/B00XVCW5A2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I started like you, trying to rebuild the old one. I had a very slow leak, like a drip a minute. Took it apart, couldn't really see what the problem was.

Decided to try the complete petcock, and glad i did. There were some slight differences. Worked great.
Comes with O-ring to tank, and that turned out to be where mine was leaking from. Old one was flattened out and hardened. I am holding on the the old OEM one as spare.

[Kbs]

Thanks for that info.  How big a job to change it out ? Thats a great idea i hadnt even thought of.

[mollusc]

Changing the petcock is simple.  Unscrew the old one, and screw the new one in its place.