Carb Problems

[derf1960]

I have a 1977 CB 750. When i got the bike the carbs were badly gunked up. I removed the carbs, replaced all of the float valves, removed all of the needle valves, cleaned all ports, reinstalled the needle valves, i reset them to the same # of turns that they were. Disassembled the accellerator pump and cleaned that up also. It was squirting fine. All of the bowls are filling and the float valves are shutting off. The bike starts right up and fires on all four cylinders and runs smooth, as long as it is 100% choked. As soon as i open the choke, it dies. I tried running a very strong solution of carb cleaner in the gas. That has not helped, maybe a little. Any help would be very appreciated.
Thanks In Advance!

[barnstormer44]

I had a simalar problem but found that I forgot to tighten the main jets with a screw driver as I put them in by hand and forgot to tighten, and they were sucking air.   I would ventrue to say you may have a air or vacume leak somewhere.  I replaced the 8 crappy honda clamps on carb rubber manifold boots.  They would not squeeze down for enough as the boots must have shrank with age.  I found some at the auto parts store that were narrow enough to fit exactly where the others did.  The normal auto width ones,, were too wide.  Check to see if the boots are cracked and leaking air.  I have a 440 Kawasaki that had that.  New boots are spendy too so you may want to clean off the oil and try some silicone first.  Did you blow out all the jets and air galleries in the carbs?  If you don't already have a can of Chem Dip, you need to dip them.  Read the directions as it will eat anything that is NOT metal.  I have a can that I have had for 20 years and it is still good.   If you do carbs, you will use it in the future.  You may have a gallery plugged and it has to have the choke on to get any fuel at all.  

Hope this helps, Dennis

[derf1960]

Barnstormer

You are really a great person to take the time to write me. Your info was considered and based on your prognosis, i think that that one of the ports in at least one carb is plugged. I unscrewed the needle valve, actually it was kind of a blundt valve, from the float bowl of the carbs, and there was tons of varnish. I purchase the Chem Dip and have been letting each carb, disassembled, sit in it overnight. Thanks again, i will let you know a status.

Sincerely Fred

[barnstormer44]

Thanks for the note back.  Better read the can as I think it only takes like 15 or 30 minutes to clean them up.   It's good stuff.   Good luck,  Dennis