1976 CB500K2...

[ST1100]

Reworked the carbs  (float movement, height and max opening angle, should do now)
Removed the stubborn oil filter bolt (air-wrench, and the thing was on with a LOT more then 27Nm  ... the nut did quite a nibbling on the flanks of the 14mm bolt head, but eventually it did came off...; then new bolt now has a 17mm head...), enabling me to replace the filter element.
Quite some goo inside the filter housing (who knows when that last oil change took place...), all carefully cleaned and assembled.
While emptying the plastic drain-pan, I found tiny metal flakes on the bottom, sized like the particles in metallic paint... dunno yet if that's cause to be concerned...
Topped up the oil, checked valve clearances again (yep, did change due the last real engine run...), in which I found the delivered valve adjuster coming quite handy.

Carefully straightened some slightly bend fins on head and cylinders and inspected the engine all around:
- seal of outdrive shaft is leaking (found a fresh drop right below), wonder if seal can be replaced from the outside...
- threads of one breather-cover bolt are stripped... as its the one right below the stub for the breather-hose not much material for installing a TimeSert there...
- apparently were 4 bolts holding the valve-cover once stripped too... thus valve-cover has been drilled and the head re-cut to M8 instead the original M6... not cool, means I'll need a new valve-cover in decent condition, possible a new head too if TimeSert won't work...

When having to do the top-end anyway, I can as well also do the bottom... more work, more $$ but I get that "metal flakes in oil" issue off my mind... 

Further:
- bracket holding rear brake light switch has been tempered with/different part welded on... will need to fabricate a new one, matching the OEM design...
- front calliper bracket has been drilled (a 2nd "adjuster bolt hole"... WTF!!) for no apparent reason...
- apparently had a PO once worn the pads down way beyond limits, so the rotor took like 4mm out of calliper part B which is therefore also done...

Filled bore of calliper part A with penetration oil to, hopefully free the piston; will try to remove it next w/e...
 

[Bryanj]

On a 500 metal flakes are usualy from where the primary chain rubs on cranckcase when chain wears but sometimes can be cam chain

[AshimotoK0]

Personally I would never run or use an engine of unkown history, without totally stripping it. It makes me cringle when DK give bikes a 'snort of ether' to check if a bike that's stood for yonks runs or not.

Take  the 'weather seized ' '69 CB350K1 I got from DK ..10k miles, perfect inside (cam/rockers/bores etc.)  but a PO has put fasteners back loose inside and I found a mangled up  split pin jamming the gearbox ..so not weather seized at all plus a dried out wasp. The 8k mile CB175K5 I just got had a broken kickstart...wouldn't turn the engine  over... I had to completely strip the engine to investigate (well bottom end at least) and found teeth broken off the kickstart pinion.. suppose I could just have used it with electric start but what havoc would bits of gear teeth done to an otherwise perfect engine? Definitely going to completely strip the 500K0

[ST1100]

On a 500 metal flakes are usualy from where the primary chain rubs on cranckcase when chain wears but sometimes can be cam chain

Also I figured primary chain as possible source... so another reason for rebuild.

Personally I would never run or use an engine of unkown history, without totally stripping it.

Ether is also not my cup of tea there... or things like push-starts... an must fire easily and on own power...
The engine turns freely by hand, all "feels" smooth and precise, all is adjusted, oil pressure light goes out instantly (thus no major bearing issue), so there was no massive argument against a test run...
Anyway, I'll need a head and a valve cover, dunno yet what awaits me on the inside...

[Bryanj]

Head and valve cover off any 500/550 will fit and look the same. The later covers had locked in spindles the rockers pivot on to stop the spindles rotating and wearing the hole in the cover oval, something the Yanks go on about a lot but I have only ever seen one---strangely the same engine i found the only 500 crank worn out i ever seen

[ST1100]

Already nailed a valve cover with named locking spindles on eBay 
And one used head resting on the shelf awaiting closer inspection, probably requiring lapping, thus new valves anyway...

Still, plasti-gauge, Graphogen and other items are already avail or on the "to get" list...

Next w/e I'll first check how my refurbed carbs do, then prep to drop the engine (already have a CB500/4 engine stand around)...

Still some headache about the fork bottoms, they appear very worn out, if I don't find a company able to fabricate tube-inserts, I'll have to seek new ones...

[ST1100]

The eBay sourced valve cover looks pretty nice on the mechanical side, outside shows corrosion, thus in need of soda-blasting and a colour coat...

A recycled DS-carton arrived today, containing a rear bumper in pretty pristine condition (cheers Bryan!!  )
Besides LH turn-signal base requiring minor adjustment, some buffing might bring it back quite good.

[Bryanj]

You are welcome, didn't realise I had recycled a DS box but I do try to keep postage as cheep as possible

[ST1100]

The red [Fragile - handle with care] sticker is very familiar; I've a couple of those boxes here too 

[ST1100]

No postings does not mean that all went dormant 

A pretty steady flow of parcels with spares is streaming in, just this afternoon I toyed with some things, like the rear bumper (which looks really great on the bike), or the Habermann (which will definitely look good on the other, '72 café bike), dropped the aftermarket VRR and installed an OEM again, which is clearing the inner fender so the tray fits back into the frame...

Lots of small things to tinker with and check out, like brake pedal vs pivot (seems I'll first have to get new pads installed) or the kickstart lever, which is a bit loose and clanks onto the clutch cover when retrackting.

A pretty new (to me) thing I'd discovered is the bracket for installing a side-stand switch!!
I kid you not, right behind the kickstand pivot, the frame-tube has a sheet-metal bracket welded on, suited or holding a switch in the style/design of the rear brake light switch, also the kickstand has an extra nut welded on, receiving a bolt/screw to attach a tension spring to operate that switch...
Checked with the 500K2 parts catalogue, no avail...
Seems I'll have to look in the 550 pages for P/N's on that...
Any idea if this even was a feature/mandatory on a 500K2? Shouldn't a sidestand switch not only interlock with clutch and starter solenoid, but also energize a warning light on the dash?

[Bryanj]

Never seen one on an old Honda and never one with a warning light, normally just stops the starter working or cuts the spark

[ST1100]

Checked the other two CB500 frames: no bracket for s/stand switch there...
Must be some crossover design meeting the 550 requirements...

Fixed the linkage for the bike-lift lowering-valve (installed two massive U-joints... the Chinese "invented" something using cotter-pins for the joints, which of course shared off at the 2nd or 3rd actuation... now the pedal linkage has no slack at all, enabling slow and precise lowering...)

Inspected the K2 a bit more:
- head bearings fully shot (nearly seizing up...  )
- front wheel bearings must have like 1mm gap, movement of rim between fork legs: +/-5mm... no wonder the calliper was binding...
- corrected routing of throttle cables by PO... now over front of frame head to LHS, through frame window above coils... moving pretty freely now...

There is supposed to a small sheet-metal cover above the steering limiter on the frame head... its badly mangled, any chance that's avail as spare?

Same for the bracket/mount holding the (rear) brake-light switch... the genuine one is gone, PO's had welded "something" onto there... like to get the original back on...

Disassembled and cleaned the genuine CB500 brake master I'd received from a mate here, really excellent condition, need to search brake-fluid resistant satin-black now...

[ST1100]

Not much happened...
Did some (parts) research, tinkered with the aux fuel IV/bottle (added hoses with quick connector, etc...)
Managed to drive the piston out the brake calliper (connect with old m/c, fill, bleed and pump out, while placing the calliper inside a bucket <splash!>... no chance getting it out with compressed air, ring fully gunked up, piston pitted, seeking replacement...)
Will change the front end and rear wheel from the yellow "spare" CB500 four (most parts missing, no title)

Found out that the two pattern ignition coils obtained have only 2.5Ohm, whilst the old OEM ones have 4.7... so the new ones are useless (unless I aim for dimming headlight and constantly drained battery...)

The more I look over and tinker with the SOHC Honda, the more I realize that such grows into an "endless" project...

So prioritising on the bikes alive and vital next w/e: my two ST1100's... small overhaul, fluid & filter replacements... 
The '94 ST is also due for alternator upgrade, swap of the lock-set (8 barrels + ignition), applying new nuke-yellow/lime livery from Bluelite Graphics, etc...