Author Topic: 1976 CB500K2...  (Read 12396 times)

Offline ST1100

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1976 CB500K2...
« on: December 12, 2015, 09:17:21 PM »
Hi all,

well, its starting, kinda...

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that hideous saddle has to go...

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rear fender beyond any attempts...

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one of many "...WTF where they thinking?!!..." moments...
Unfortunately is that K2 rear bumper/grab rail missing... will need to chase that down...

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see above...  :(

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main-stand pedal actually cut off... good that I've stashed a spare in mint condition...

« Last Edit: December 12, 2015, 09:38:27 PM by ST1100 »
not done yet...

Offline ST1100

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Re: 1976 CB500K2...
« Reply #1 on: December 12, 2015, 09:20:46 PM »
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silencers and downpipes not looking good...
And note those passenger pegs, their massive, like filed out a lump of steel...

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uh-boy... AME-bling... can you spot the mistakes?

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more bling-bling...

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interesting disk setup...
« Last Edit: December 12, 2015, 09:36:27 PM by ST1100 »
not done yet...

Offline ST1100

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Re: 1976 CB500K2...
« Reply #2 on: December 12, 2015, 09:24:53 PM »
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messed up clocks...

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plumber's hose-clips...  :o

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a piece of garden hose serving as case vent...

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IGN lock bracket: mounting tabs seriously bend and something rasped down...  :-\

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again: what were they thinking...
not done yet...

Offline ST1100

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Re: 1976 CB500K2...
« Reply #3 on: December 12, 2015, 09:27:20 PM »
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no comment...

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what IS this???

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definitely some DIY sizzling... 
not done yet...

Offline ST1100

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Re: 1976 CB500K2...
« Reply #4 on: December 12, 2015, 09:29:03 PM »
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fuel tank in astonishing good condition though...

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even the mesh/filter still alive...
not done yet...

Offline ST1100

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Re: 1976 CB500K2...
« Reply #5 on: December 12, 2015, 09:35:01 PM »
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prepping the shipment to Menno...

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another disaster area...

Apparently the lug for the brake pedal pivot has been torn off once, and "sizzled" back in place...
Bad that the tab with the pedal stop-bolt is missing...
Swapping the frame won't be an option, as this will mean to loose the original title of that motorcycle...

So lots of work there...

First I'll get switches, electrics, throttle and clutch cables working again... swap the carbs out...
Give the engine some service (valve clearances, compression check, etc...)  to check if its even firing up and running...

 
not done yet...

Offline royhall

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Re: 1976 CB500K2...
« Reply #6 on: December 13, 2015, 12:39:51 PM »
Crikey, that old girl is going to need some love. Good luck with the build.
Current bikes:
TriBsa CCM 350 Twin
CB350F in Candy Bacchus Olive
CB750F2 in Candy Apple Red
CB1300SA in Black
Triumph T100C
Suzuki GS1000HC (Bastard tried to burn me to death last night)
CB450K0 Black Bomber (current project)

Offline ST1100

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Re: 1976 CB500K2...
« Reply #7 on: December 13, 2015, 07:01:16 PM »
LOL!  ;D Any affinities to Oz?  ;)

Removed that badly mangled rear fender... and then some...
Rear t/signal posts had been painted over, will see if they can be brought to shine again...
Wiring harness is a mess... requiring replacement was expected...
Discerned a not original regulator with wider housing, interfering with the inner fender, bending the electric base outward...
Freed the stubborn, corroded shut filler cap... dipstick bone dry... case reeking like old transmission fluid...
Removed one of those fancy, also stubborn AME tappets (must have been installed with an impact wrench back then  >:( ), to pour 1ltr fresh 10W40 down the galleries... no instant leaks spotted  ;)
not done yet...

Offline ST1100

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Re: 1976 CB500K2...
« Reply #8 on: December 15, 2015, 07:32:05 PM »
Carb isolators, intake rubbers and all cables (throttle, clutch) ordered... in stock, gonna pick them up Friday...
Will see if I get to tune the engine this w/e...
not done yet...

Offline ST1100

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Re: 1976 CB500K2...
« Reply #9 on: December 16, 2015, 08:47:10 PM »
Dropped this seller a line if he could also assembly a tool-set for a CB500K2...
http://www.ebay.co.uk/itm/252161743335?ru=http%3A%2F%2Fwww.ebay.co.uk%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D252161743335%26_rdc%3D1
Guess what, he does... will ease the task at hand tremendously  8)
not done yet...

Offline ST1100

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Re: 1976 CB500K2...
« Reply #10 on: December 18, 2015, 09:51:14 PM »
Removed the carbs today... use of a heat gun does help, but them old rubbers proved to be stubborn as a mule...
Couldn't get the isolators off the intakes though, so I sliced the open ends with the wire cutter and tore them apart...

Removed the plugs, all quite sooty... and the wrong type: D8EA instead of DR7ES installed...
Odd that one has to remove the rev cable for proper access... and good that I have a number of OEM Honda tools (plug socket) around...

Threw the lens-end of the endoscope down the plug threads, huge deposits on the crowns... only on #1 I can make out the embossed number, the others have a too thick crust...

Used an oiler to get a few drops of 10W40 into each cylinders...

Checked valve clearances, odd procedure, some were tight, did 3 runs to be sure... at least the engine turns freely by hand...

Points plate looks OK, contacts corroded, isolation of cap cords crumbled off... new parts already on the shelf...

Installed a € 25,- replica ignition lock, attached the boost-starter, flipped the switch and... we've power!
- oil warning OK
- neutral dark, either switch dodgy or bulb burned out, will sort that out later...
- t/signal/s working, astonishing
- HIGH/LOW working, same...
(switches are in really bad shape, some only have the metal-prong left, but their all working!)
And the horn resembles a croaky road-runner...  ;)

So I broke out the compression tester:
#1: 5.7 bar
#2: 6.0 bar
#3: 6.0 bar
#4: 0.0 bar... zero, zilch, nothing... bugger...  ???
Can't tell yet if its burned, bend or a shaft seizing in the guide...

At least I now know that oil pump and switch are working...

So, should I drop the engine out the frame right away, or start by removing only the head with case still installed...
not done yet...

Offline Oddjob

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Re: 1976 CB500K2...
« Reply #11 on: December 19, 2015, 12:45:29 AM »
You can remove the plug in No3 cylinder quite easily with the genuine Honda plug spanner that comes with the bike. The genuine version has a knurled top and dramatically thins near the top, some sellers these days are selling what they claim are genuine Honda plug spanners for the CB500 and they look nothing like the original. I sold a NOS one last year, shame I didn't take a picture of it so you could compare yours.

Likely a valve has rusted or seized into the valve guide, can you see the valve going up and down as the motor spins?
Don't play stupid with me, I'm better at it

Offline ST1100

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Re: 1976 CB500K2...
« Reply #12 on: December 19, 2015, 10:15:35 AM »
You can remove the plug in No3 cylinder quite easily with the genuine Honda plug spanner that comes with the bike.
LOL!  ;D
Somewhere out there must be an ocean floating with "lost" OEM tools  ;)
No such thing on a 40 year old bike, dunno what people do with them, I carefully keep mine in place and shape on all my vehicles...
I used a long Honda plug spanner with 12mm hexagon head for removal (I had floating around in one of my treasure chests), but not the Honda spanner (will have to get me a proper sized socket for the ratchet kit ASAP...); still found it safer to remove the tach cable, also hose and adaptor of the compression check manometer like the clearance gained.

Quote
Likely a valve has rusted or seized into the valve guide, can you see the valve going up and down as the motor spins?
Rockers moving properly during valve clearance check, valves didn't appear to remain stuck open then, nor would the visual "height" of the adjuster bolts inside the rocker arm suggest such...
I suspect a shot outlet valve there, but will check again today, this time also armed with a fully charged car battery, since the small boost starter thingie doesn't deliver much "omph" (its Chinese battery is only sufficient for about 3 starts on a good, promptly firing engine like the 16 valve V4 of an ST1100... I actually had to recharge it between testing #2 and #3  ;) )

Since the frame needs sanding and paint, I'll have to drop the engine out anyway; I'd only like to collect an "inventory" while all is still together in working order...
not done yet...

Offline Oddjob

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Re: 1976 CB500K2...
« Reply #13 on: December 19, 2015, 08:52:05 PM »
There aren't that many things that can cause zero compression. However if the engines been stood for a long time the list does go up dramatically. Possible the valve seat has rusted so much due to that particular valve being open when the engine last stopped that even though the valve now shuts the corrosion is allowing the compression to escape. Hole in top of piston but you say you've looked at the pistons with an endoscope so probably not that. Stuck piston rings but then the oil you squirted down should have sealed it enough that you get at least some compression. Totally blown head gasket I suppose, any sign of an old oil leak? The culprit should be pretty clear once you remove the head.

Yeah, makes you wonder where all the old tools go out of the set, some lost by the road side I suppose, others lent to mates and never returned, most however I suspect are kept by the previous owner on the "off chance" they'll find a use for them but ultimately get thrown away as they really are very cheaply produced and only really good for roadside repairs.

My 1972 500 still has the original toolkit and it's all there, hardly ever used it TBH except for the plug spanner which because of the No3 cylinder got used all the time.
Don't play stupid with me, I'm better at it

Offline ST1100

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Re: 1976 CB500K2...
« Reply #14 on: December 19, 2015, 09:47:15 PM »
Ha! Made it and freed the bugger up again  8)

After the valve clearance got "tight" again after 2~3 cranks, I went to a desperate manoeuvre and poured like 10ml Datacol (carb cleaner fuel additive) down each plug hole, plugged them, gave the engine a brief crank to squirt the cleaner around and let it sit for about an hour.
Then raised the paper towels a bit from the plug holes and cranked the engine a couple of times to belch the stuff out... yuch, quite some black goo...

Then peeked in with another, better endoscope with periscope bit:

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Yay, the distinctive mark indicates the valve is now actually touching the seat  :D
Gave the valve clearances another run, #4 out again tight, loosened it, another 5~6 cranks (the B.A. car battery serves well) and it seems to have settled now.
So I did another compression check: 6 Bar on all 4 now!
Still only half the pressure a new engine would reach, but I a) don't know how good my compression test kit truly is, or b) how corroded the valve seats are, c) condition of rings, d) etc...

With all the tinkering not only the oil pressure is up at the instant, with some oil gushing around in the case also the neutral switch decided to get back into working state again, so we've a green light there  ;D

Checked the ignition next, both capacitors dented + cable insulation thorn -> replaced.
Adjusted points gap and checked timing, gave it a run, no spark on #1 & #4...  :o
ID-ed LH point as culprit, threw a new one in, now spark on all 4 cylinders, good  8)

While at it I removed the RH switch-pod, freed the throttle pipe, installed new throttle cables and put all back on again...

Will see if and how I'm motivated tomorrow to a) get up early, b) install a cab-bank and c) pour some 98oct into the w/shop tank bottle and try firing the bugger up  ;)
Only a brief run to get the oil warm so I can drain it and fill new one.
Once cooled off I should check valve clearances again in case rust & deposits have burned off the seats and valves...

So that's the current state now:

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And that's the helpful plug socket I managed to unearth

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« Last Edit: December 19, 2015, 10:10:45 PM by ST1100 »
not done yet...