1981 cb750c carb issue

[Cheryl]

I recently inherited this bike, and I'm trying to make it work.  The gas tank is crap and the petcock is missing, so I rigged a bottle and hung it from the ceiling of the garage like an IV system.  I got it running...but the carbs were leaking fuel from the overflows (all four.)  So rebuilt the carbs...and now its leaking pouring fuel from the overflows AND the air filters  EXCEPT when the gas is very low then it runs perfect.  Here is my question:  I was wondering if the petcock has a vacuum system, and possibly the IV rig that was made as causing the problem?  TOO much gravity for the gasoline so its just flooding the carbs?  Or I missed something and just have to clean the jets...again ;)

Also If somebody could take a pict of where the choke connects to the carb...or direct me to a pict of one.  One piece looks bent, and its keeping the choke from operating properly.  

This is a fun project...but I'm stuck!  

[Cheryl]

OH!  And if anybody has a cafe gas tank that they would be interested in selling, let me know :)

[kramit]

Hope picture helps !!!

Kramit

[kramit]

Also cheryl if you can find a old lawnmower gas tank you can mount on motorcycle with bungee cords,
and drive around or sync carbs. just make shure gas line has filter, and when turning either direction gas line is long enough so not to pull of carb. This way you can always test drive, have better access to carbs.
make sure to secure tank with plenty of bungee chords. Also secure with small clamps were hose connections are made. see picture.

Kramit

[Cheryl]

Thanks for the photo that helps!  I will try and post a pict of ours.... but I think the clutch is in working order now.

I never thought of using a lawnmower gas tank!  Very innovative.  Eventually I want to get the cafe racer tank...but thats $500 spair dollars I don't have right now.  

I think there might be a problem w/the automatic pet cock.  I took it apart and the rubber inside was sticking to one side and seemed a bit fragile.  We're soaking it overnight in lithium grease to see if it will bring some life back to it.  I'll also check other pages on how to adjust the floats...as they are all plastic I really don't know how that is done.  

Thanks for your help!  

[TOOLS1]

Before adjusting the floats; make sure they still float. Sometimes when they get old, they become logged, and will not float right.
TOOLS

[Cheryl]

I am 99% sure they are okay.  I did the visual/tap/float in the water test on them, however I didn't plunge them into the water to see if there were any bubbles.  There wasn't any gas leaking from them after I took them apart again....but it could have escaped from the floats before getting to them.  

I have very little experience w/carbs...if one issn't working correctly, since their lines are all connected...will all will leak?

I wish I brought the carbs home w/me...this is driving me crazy reading about stuff when they are 15 miles away ;)

[Cheryl]

Okay PROBLEM SOLVED!!!  The problem was not the carbs...but it was the fact that we hung the homemade gas reservoir too high!  The gravity was just too strong.  After the reservoir was placed lower, around where it should normally be, then all was fine!  YIPPIE!  

Now onto something a bit more fun ;)