In
an effort to find a new home for the Tracy-bodied CB400F, my trip to
the El Camino College swap-meet in October yielded a pair of vintage
Honda tiddlers, as part of an exchange of vehicles. Outwardly, they
looked like fairly intact machines, reportedly both running within
the past few months. Well, you know how that story goes…
Exhibit
1. 1967-8 SS125A 125cc twin, showing about 4k miles on the
speedometer. Seller claimed to have purchased from an eBay sale and
when it arrived and was started up it smoked heavily. One would
imagine that the rings were stuck from long-term storage, so a quick
top end job might set it right. The right side clutch cover had all
the Phillips screws replaced with Allen screws, indicating that
perhaps someone had been inside the engine for unknown reasons.
The
bike came with a wiring harness in a box, which turned out to be the
wiring harness for the bike; not a spare. When the battery cover was
removed, the back side of the ignition switch is revealed and it was
discovered that all of the connector wires were cut off from the
switch. Likewise, the wire ends for the stator connector were cut
off, as well. There were two wires leading down to the ignition
points connection, instead of just one. The wiring showed signs of
newer shrink wrap over the wiring connections, leaving me with a
mystery. When mentioned to the previous owner, he said that the bike
had been at “Charlie’s Place” in Los Angeles where it was being
test fitted for an electronic ignition system. This made more sense,
but unfortunately, the project seemed to have been abandoned and I am
left with wiring repairs to make. I have a box of misc wiring
harnesses and electrical bits, so was able to prune off a couple of
matching wire connectors with short leads of wire and patch the cut
wires back together again.
I
dropped the engine out of the chassis, which is really only held in
with 4 bolts. On the bench, the top cover was removed and I was
dismayed to see a lack of oil on the cam/rockers and what looked like
some heat-related scoring on the cam lobes. The head was removed and
mostly just soft carbon was left on the pistons and valves. These
engines have little valve stem seals on the exhaust sides, which can
harden and then allow some oil to seep into the engine causing smoke.
The
cylinders came up next and the pistons were not seized and the rings
were all free in the ring lands. Removing the rings and setting them
back into the bores to check end gaps revealed little apparent wear
on all the parts. I planned to reuse the rings, but noticed a ridge
across the top edge of the ring, due to some kind of unusual wear.
The 230 code rings are getting scarce and the part number has been
superseded to the CB125T model, which uses a 3-piece oil ring set,
however that bike was never sold in the US, so parts have to come
from somewhere else. I found a salvage business who was parting out a
couple of engines, so ordered a used set of pistons/rings, just to
get the ring set. Before that, an eBay seller had “CB125” ring
sets, which were 44mm but the rings were 1.5mm thick and I needed
1.14mm rings, so those went back to the seller. The set of used
CB125T pistons/rings arrived quickly from the eBay seller and
thankfully they fit right in. It was interesting that the wrist pins
were shorter/lighter than the SS125A versions.
Attention
was then focused upon the clutch cover where the oil pump lives. The
Allen screws were removed and the cover lifted away. The retainer
bolts for the oil pump are secured with a metal strip that has tabs
to secure the bolts from backing off. The tabs were in place, but the
whole pump was loose on the engine case. Removal of the clutch
assembly and oil pump revealed small fragments of a home-made gasket
that is supposed to seal the pump to the engine case. Apparently the
gasket failed and the oil was squirting out back into the lower end
instead of being circulated back up to the cam and rocker arms.
Cleaning
the cam and rockers on a soft wire wheel revealed only minor wear
marks, so apparently the engine was only run briefly before someone
decided that there was a problem with the engine. The cam and rockers
were reused, after the valves were de-carboned and new stem seals
installed.
A
new OEM gasket kit was obtained from an eBay seller, which included
the thin paper oil pump gasket, so all the parts were cleaned for
reassembly. Not much can go wrong with the oil pumps, as they are a
plunger type driven off of the back of the clutch basket and there
are two check valves keeping the oil flow going in one direction. I
removed the steel balls to clean the pump housing and noticed a thin
ring of rust around the middle of the ball where it had been sitting
in the same location for years and some moisture in the oil had
created a rust ring on the check ball. So, a word to the wise: check
your balls before reinstalling the oil pump! These pumps were used on
many Honda 125, 150, 160, 350 and 450 twins, so keep this caution in
mind if you are having oil pump problems.
The
chassis needed new fork seals and boots, new battery, new mirrors,
new cables and lever sets. The fuel tank looked to have been coated
with a silver coating on the inside, but the outside appeared to have
been painted with a brush, perhaps with the same material! The
petcock needed replacing, as well. I discovered that the cheap
Chinese made petcocks, offered as replacements for the SS125A are not
a bolt on fit. The recess for the attaching screw is too small for a
common 6mm screw and the sealing washer. The whole standoff for the
fuel tubes was too big to fit into the fuel tank opening slot. I
eventually was able to get it fitted to the tank, but don’t trust
that it will be leak-proof, so bought an NOS Honda petcock for $40 as
a backup.
The
bike finally fired up after a puzzling event, where the ignition
timing was suddenly about 45 degrees off from where I had eye-balled
it during the engine build. Oddly, Honda had put two sets of point
plate mounting screw holes in the outer cover and when I reset the
plate to the previously unused screw holes, the timing lined up
successfully.
The
engine started up quickly after that, with no smoking at all. A quick
check of a tappet cover showed oil flow to the top end in proper
quantities. In my excitement to drive the bike, I failed to check the
tire pressures and got a flat rear tire about 2 blocks from home!
Fortunately, I had a spare inner tube on hand and made the repair
easily. The last step was to replace the fork seals and boots with
new parts, so now it is a fully-functional SS125A.
The
mufflers looked pretty solid at first, but then I noticed that the
baffles were gone out of the back sides. The poor little bike seems
to have had a rough life in the past 52 years in only 4k miles of
travel under its own power. Such is often the fate of these little
low-cost machines from the 1960s.
Exhibit
2. This 1971 SL100 that only had about 1300 miles on the odometer.
It too, was supposedly a runner, but had been hard to start and keep
running according to the seller. The first thing noticed was that
there was about 1” of battery acid in the battery. These are
battery-powered bikes, so if you don’t have a good battery, it is
almost impossible to make them run.
Looking
closer at the bike, I saw that the stem for the speedometer was
broken off, so the meter was junk. The tires all appeared to be stock
originals with little wear. Again, all the cables and levers needed
replacing and the left side fork seal was weeping oil down the side
of the fork slider. The fuel tank seemed to be relatively clean, but
the petcock was rotting away. Both bikes needed new petcocks, which
are available online for less than $10 each, but they are, of course,
made in China.
The
little plastic side covers, which fit all the SL100-125 models, have
become scarce and even reproductions are priced over $100 each now.
Both are missing from the bike. The headlight rim was taped to the
headlight shell with electrical tape which is never a good sign. I
ordered a reproduction shell from Thailand and that solved the
problem, but the holes for the bolt spacers were too small. It came
in black plastic, which I tried to paint with chrome paint, but it
didn’t turn out very nice.
After
going through the basic tune-up process, the bike initially started
up and ran, backfiring back through the carburetor. The ignition
points had closed down so the timing was about 5 degrees after TDC
instead of 5 degrees BEFORE TDC. Opening the point gap brought the
timing into specifications, but suddenly the bike wouldn’t restart
despite having all the ingredients of spark, fuel, air and
compression. Rechecking the timing with a test light, I discovered
that the ignition switch was intermittent, so turning it ON didn’t
mean that you had power to the coil in every instance. I installed an
aftermarket ignition switch from a CB350, using just 2 of the leads
and now the ignition is reliable.
Then
engine sounded good once it was running, with no signs of smoke, but
the initial ride around the block revealed noticeable primary gear
whine in all gears. I drained the oil and pulled the clutch cover to
check for obvious damage, but the only anomaly was a somewhat loose
clutch basket on the input shaft. The primary gears are straight cut
between the crankshaft and clutch basket, so as the load is put on
the clutch, the gears fail to mesh squarely, probably causing the
noises heard. Honda did upgrade the kickstarter shaft and a couple of
gears in these engines, so this one probably needs the upgrade, but I
am not going to do it.
The
SL100 turned out to be “not on file” with DMV, so fresh paperwork
was needed to get a title for the bike, plus a trip to CHP offices
for them to do a bit more research on it. The SS125A had a title from
Indiana, sold from a guy in Michigan and finally to the LA area
seller that I got it from. He had paid some fees to get a title for
it, but never got the engine numbers inspected to complete the task.
The transaction was still in the DMV system, so I was able to get
some of the current charges deducted from what he had paid
previously.
ALERT
for California residents! When I took both bikes down to DMV, for
initial verification of the numbers, the bikes had a few parts
missing (SL100-headlight and SS125A headlight, mufflers, tank and
seat). I have taken partial bikes to them for the last 10 years
without comment, as long as the engine was installed in the chassis
when inspected. NOW, all of a sudden, DMV won’t inspect what they
call incomplete bikes or “project bikes.” After wrangling with
the two inspectors for a few minutes, I left the inspection lanes and
took the paperwork inside for my desk appointment. The lady at the
desk confirmed that CHP had come down on them for inspecting
incomplete vehicles so they made up a new rule to conform to the
edict. So, if you live in the Golden State, put all the pieces on
your bike before you head down for a DMV or CHP inspection now.
Unfortunately,
these little bikes can easily turn into a money pit, once you start
replacing even the basic items, like cables, levers, petcock,
battery, tires, and other consumables. You better be in love with
your new tiddler project, if you plan to embark upon a restoration or
even an extensive revival enough to get them fully functional and
safe to ride again.
Bill “MrHonda” Silver 11-2019
Use a CA DMV authorized VIN VERIFIER to avoid CHP inspection hassles and stupid obstructions.
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