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1976 CB500K2...
ST1100:
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...
ST1100:
--- Quote from: Oddjob 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.
--- End quote ---
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?
--- End quote ---
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...
ST1100:
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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Bryanj:
That manual you have there is only for the VERY early 500 and has some glaring inconsistencies with the later K0 and onwards
ST1100:
Thanx for the info, I noted that the engine pics do show the edged K0 case, but till now the manual hasn't let me down...
And I couldn't locate a distinctive CB500K2 manual anywhere, they all offer only '71~'73...
Only the parts catalogue (which is the most helpful yet) is a K2 edition
Even DS doesn't list a K2 ED model, only the US K2 which differs...
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