85 CB700 misfiring on 3

[carters2]

My buddy has a 1985 CB700 that has not been used in quite some time and is not running correctly.  The bike will only run while it is choked even when the engine is fully warmed up.  The spark plug wires and boots looked pretty beat up so we replaced all the spark plug wires with brand new ones.  The bike still is not running correctly.  When it gets higher into the RPM range it seems as though it is running on all four cylinders but I am not sure.  The exhaust pipe for the 3rd cylinder is noticeably cooler than the other 3 pipes but still has some heat to it.  All four carbs are new and were put on the bike and I was told that they were already synced up.  The fuel in the tank has since been replaced but the fuel that was in the tank was treated with seafoam.  I am not sure what is going on here and I want to avoid buying a whole bunch of parts that I don't need.  Does anybody have any idea what may be going on here?

Other facts...

1. All spark plugs are new
2. Visual inspection shows we are getting some spark on all 4 cylinders (not sure how to tell if it's strong enough)

[gammer]

Did you or your friend do the carbs? Or did someone else do them before they were sold to you? If its the later, then all bets are off. I'd pull the carbs and clean them myself. Here is a link on how to clean them using Pine Sol...that's right Pine Sol:
http://nighthawk-forums.com/index.php/topic,4472.msg54844.html#msg54844

Also, a true syncing must be done when the carbs are on the bike using a carb sync tool (manometer). Even taking freshly synced carbs off one bike and installing them on an identical bike, can throw the sync off.
Lastly, syncing doesn't cure running issues. It mainly makes a proper running bike run smoother and offer better throttle response and perhaps better fuel mileage.

[carters2]

My buddy bought a bank of 4 new rebuilt carbs.  The guy said that it had already been synced up, cleaned, and jetted for a cb700sc.  I think I will try to clean that carb and see if I can get it to run.  As I said before it seems to run fine when revved so maybe the pilot jet is clogged solid and once it is getting on the main jet it is firing just fine.

[gammer]

What does the screen look like in the bottom of the tank? Is it dirty? Is it even there?
Also take the petcock apart and clean it.

I'd clean all the carbs at once. Check that link I posted in my first post. It shows how to clean the carbs without separating them...doing it as one bank.

[carters2]

That was the first thing we looked at.  The petcock is clean and flowing fuel.  I will try the method posted in your link

[ariwhiteboy]

  to the forum.  Whatkind of shape are the coils and wires in? 

[carters2]

If you are referring to the wires that are providing the coils with 12v they are in good shape.  The spark plug wires were destroyed but we have changed them and it made no difference.  This morning we are pulling off the carb bank and cleaning out all the carbs.  I will let you guys know how it works out.

[carters2]

Well i pulled the carb bank and cleaned everything up.  3 out of the 4 pilot jets were partially or fully clogged.  Put the whole thing back together and it's running great now!