Topic: CB550 engine in a CB500 initial setup

[JBMorse]

Hi folks,
Earlier this summer I picked up a CB550 engine to swap into my CB500 while the original CB500 engine is apart for the world's longest rebuild. I got some great advice here about how to set up the carbs and now that everything is installed I am having a hard time tuning it.
Here's what I'm are dealing with:
Bike: 1971 CB500
Engine from a '78 550K, carbs from the original CB500K engine, stock jetting, needle clip in 4th groove.
Intake: Stock airbox with UNI foam filter, exhaust is a 4into2, possibly older MAC which I believe is close to stock in terms of back pressure.
The carbs were apart, cleaned, float levels checked, new rubbers on both sides of the airbox.
I also set the valve clearances, cam chain tension, timing, points, and installed new plugs. Air screws on the carbs were set 1.5 turns out. Carbs were bench synced than vacuum synced once on the bike, as best I could given the following circumstances:

So now that it's all together I am having some trouble with the initial tuning. The bike won't start and idle without some throttle applied. It starts to die when the choke is closed. I believe it's acting like it's getting too much gas. I plan to remove the carbs again and recheck the float levels. I'm not sure what else to check. Is there anything else I should look for?
The other problem I have is the clutch rattle. I was terrified when I first fired up the bike because I thought I was hearing an extremely loose cam chain, but after adjusting and trying the clutch I realized it was rattling quite a lot. Maybe I don't have it adjusted quite right? I could adjust the CB500 clutch with my eyes closed but am not used to the CB550 clutch.
Thanks!

[dave500]

been right over your ignition?im running original 500 carbs on a 550 motor,38/100 jets middle clip,stock air box and 4-1.

[JBMorse]

Yup, timed the ignition statically and set the point gap. The coils, wires, plug caps, and plugs are new (recent I should say). Tonight I will recheck the timing and point gap. I think I need to double check everything I did actually because it seems as though this bike should be good to go. I think I'll take the carbs off and check the float levels and look for any blocked passages again, then go through the 3k mile tuneup items again and see where' I'm at.