Running problems- help with diagnosis please

[work9to5]

Bike is a 78' Honda cb 550

A little over a year ago I pulled it from PO garage

Changed/adjusted-
points
carbs- full rebuild
battery
removed push throttle cable
4 into 1 carpy pipes
air pods
other cosmetic changes

have been driving it the past eight months with almost no problems

Two weeks? ago had a problem at a stop sign. When accelerating after stop experienced loss of power. couldnt get it above 20mph in any gear. Bike would come back to normal power (jump) after reving gas. Problem has gotten worse over the past week. Have to keep it rev'd to 2000rpms at stops to keep bike on. It is not ridable now. Still drives just almost no power.

checked/changed yesterday
-changed oil, was dirty but nothing pointing to a problem (last change was a month and a half ago) before changiing oil added seafoam to tank and case to see if it was just a moisture problem (no change)
-changed spark plugs- they were all black pic attached
-checked fuel lines, fuel is getting to carbs freely

other symptoms-
problem started where i could drive it out- has worsen'd to where bike will not drive up any incline
loss of power, cant get it above 10mph
sound has changed drastically- still even and balanced but tone and pitch are different
have to keep it rev'd to 2000 rpm even while braked at a stop or in neutral
if i dont give it gas it shuts off
if i pull choke bike shuts off
all sparks are firing- all pipes getting hot
dont understand that this could be a carb problem- i rebuilt them 8 months ago

its a 78' honda 550 with 20,000 miles roughly
was running fine for the past 8 months

Any advice appreciated and thank you in advance!
full link can be found here - http://www.dotheton.com/forum/index.php?topic=38679.msg548818;topicseen#new

 

[teazer]

Which two exhaust pipes are hot and which two are cold? That should point you to the offending coil, points and condensor.

 

[work9to5]

All pipes are getting hot. all sparks are sparking. only posted a pic of two of the plugs because i could only reach two in the garbage bin. All four look the same though.

 

[forcefanajd]

Check your timing, either point plate spun or cam chain jumped by the sounds of it. Was the cam chain making any slapping noises?

 

[dualitymike]

How's the charging system? If your battery keeps going dead, could be your alternator is on the way out. By keeping it above 2000 rpm, you'd be producing more power from the alternator and using less from the battery than if you're idling. But if the alternator is dying and your battery charge is low, it'll cause a stall situation at lower rpms. I own two 1977 550's and I always suspect, and check, the charging system before anything else. If your spark is weak, it could cause intermittent misfires and black sooty plugs. Here's a link to the best charging system troubleshooting guide out there.

http://www.electrosport.com/technical-resources/library/diagnosis/pdf/fault-finding-diagram.pdf