1967 Honda C77 "Dream"
exhausting every thought to get the Dream running again I finally
decided to give up my hopes of riding it this fall and decided to tear
the engine down and find out what was wrong with it - when I got it
opened up, I am glad I made that decision. All three rings on both
pistons were stuck solid - no wonder the compression was nonexistent!
Running it in this condition would have done far more damage. A new
gasket set, an oil ring set, and two sets of piston rings are all on
order. The valves have yet to be inspected but look pretty good so far.
The cylinder bores also look amazingly good (considering the condition
of the rings!)
honed the bores and they cleaned up fine. I can see where the engine
sat with the pistons 75% up the stroke and one valve was open so there
is a little more corrosion at that spot but no ridge or pitting. Almost
all the damage seems to have been done while it was sitting.
rings, on the other hand, were stuck harder than anything I have ever
seen before! I had to beak each ring into segments and then drive the
pieces out with a skinny punch! After getting the rings out, I gave
each a good wire-brushing and then chucked them in the lathe to clean
up the ring grooves.
I checked the valves and they are all
serviceable - not like new but good enough. Spent the rest of my shop
time this morning cleaning up parts and scraping old gaskets off.
split the transmission case to diagnose the intermittent kick-starter
and the ratchet looked in good shape. It is most likely that the
kick-starter gear was not engaging with the transmission properly.
Time to start washing all the parts and clean them up for reassembly. I
had the lower end back together while waiting for parts so when the
seals came in, it was down to work. Less than 24 hours to an antique
motorcycle gathering and the objective is to have the Dream running!
Rings on, pistons back in the cylinders, and with the head on, it was time to set the cam timing.
When you are one old woman alone in the shop, hanging an engine is a P.I.T.A.!!! But it got done with only minor swearing ;)
Brake pedal, foot rests, exhausts, tank, etc. back on and it was time for the acid test.
6 hours from receipt of parts to having the bike running again! Not bad for an old broad LOL!
the engine rebuild, I had a lot of trouble with the bike running
excessively rich and could find nothing specific wrong with the
carburetor. In the end I made some modifications (not recommended) to
down the problem(s) with the neutral switch! The first one, as I was
advised it probably would be, was the wire broken off the neutral
switch - fixed that (after breaking the screws loose with a chisel!)
Second problem was that the bulb keeps falling out of the little right
angled boot and landing in the bottom of the headlight enclosure -
fixed that with a little contact cement!
re-reading the carburetor section of the service manual, I figured
out I was turning the "air screw" the wrong way to lean the low speed
Got the fuel tank back on after making a new
fitting to install an after-market petcock, put the carb back together
and put it back on and tested for leaks or seepage - none.
Since the Dream was almost buttoned up, I decided to put the right cover on and see how it runs.
has the occasional miss at mid-throttle but other than that it is
running PDG (pretty damned good)! I may have to shield the lead for the
electronic ignition to get rid of the miss 'cause it runs pretty close
to the right spark plug lead and I still have to set the ignition
timing at high RPM but we're getting close.
Adjusted rear brakes, repaired brake light circuit, repaired tail light circuit, and installed air filter.
the starter and the starter clutch - still needs a new starter chain.
Carburetor still needs to be tweaked at mid-range.
Time to get both Hondas cleaned up for an antique motorcycle show.
Dream was still not running the way it should and I had checked
everything else so I dug into the ignition. I scoped the coil primary
and everything looked fine.
dug out my old timing light and found that the timing was almost 30
degrees advanced (even though the static timing was set dead-on). I had
to twist the magnetic 'top hat' (the electronic ignition pickup) quite
a bit to bring the timing back to where it should be and now the bike
runs fine, both at idle and going down the road!
Though I hoped to get the
engine broken in and do some riding before the cold weather sets in, the Dream had other ideas.
riding it a few times, it started running a bit rough again one day and
wouldn't restart the next day! I think I am going to rename it the Honda
The problem this time traced down to the
high-tension side of the ignition coil going weak - almost no spark -
AND the plugs being badly fouled.
I had a similar ignition coil
in the junk box, extended the spark plug leads, and mounted it on the
original coil bracket and the bike was running again. (A new ignition
coil is in the mail.)
A little minor repair work after its first
night drive last night - repair the headlight adjusting mechanism and
provide a ground to the speedometer case so the speedometer light works
and adjust the brakes again so the brake light works. (New brake shoes
also on order!)
Fix one thing, three more break! ***SIGH***
After all the above repairs, I still had a problem with the mid-speed mixture adjustment - I just COULDN'T
get it adjusted properly so I purchased a second salvaged carburetor
and installed it without opening it up or changing any
adjustments. It worked substantially better and I was able to adjust
the mid-speed mixture properly.
On close examination and
comparing the two carburetors, I found the salvaged carburetor had an
O-ring seal on the mid-range mixture adjustment that the original
didn't have - neither was there a replacement O-ring in the carburetor
found a suitable size O-ring in my shop stock and installed it on the
original carburetor, installed the carb, and took it for a test ride -
HUGE improvement! The mid-range mixture is now adjustable in the proper
All that is left (I think!) is to tweak the high speed mixture to get some more power.
a couple more adjustments to the main needle, the performance is now
acceptable. It will get a few more 'test drives', as long as the
weather holds, and then it will be time to tear everything down for
polish and paint.
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