1974 CB550K Strange Coil Behavior

[Dr. Frankenstein]

I have a weird 'thing' going on with the coils on my 1974 CB550K - the bike ran last fall, right after I finished rebuilding it, but then winter came and I put it up for about 6 months; I tried starting it up yesterday and it runs on cylinders 3 and 4, but not on 1 and 2. The pipes on 3 and4 get hot, like they should, but 1 and 2 are stone-cold. I think it's weird because coil #1 (with the blue wire) fires 1 and 4, and coil #2 (with the yellow wire) fires 2 and 3...I've tried switching the wires and trimming the spark wires and still have No Joy. I'm thinking it's either the plugs, timing or (maybe) the capacitor - what do you think??  I feel like this is an easy fix, but I'm just looking for ideas here. 

[K2-K6]

Squirt some e-z-start (or carb cleaner) into 1 & 2 carbs to see if its fuel or sparks.

If both 3 & 4 are firing , that suggests the ignition system is functioning at least. Also check for spark at 1&2.

[exvalvesetdabbler]

Crack open the drain screws on the float bowls and see what comes out if anything. I have had the float pivots and float  valves glued up with old fuel residue and fuel not getting in.

1&4 share one set of points and coil 2&3 the other point/coil so  it
Sounds like the coils are sparking but just as a check, plug a spare spark plug into the plug cap that's not firing and rest it on some metalwork and turn the engine over just to be sure  Some folk have been known to stick their little finger up the plug cap but I wouldn't recommend it, tried it once quite painful.

Assuming the plugs are reasonably clean and not wetted with months old fuel residue.

Regards
Dave

[Bryanj]

The points are corroded and pivot stuck, spray liberally the complete ponts plate with wd40 and drag some folded wet n dry through the contacts then exercise the pooints with a screwdriver

[deltarider]

My guess is: fuel related. Drain carb 1 and 2 and check fuel arrives and floats move. No need to remove the rack. Check fuel exits from both pipes at the petcock by blocking one pipe at the time with your finger. If both are free, connect tubes again and continue with tapping the carbbowls with the stub end of a screwdriver. You can also - drain screws removed - flush the bowls by opening and closing the petcock and tapping at the same time. Abstain from extra inline fuel filters.