SE Michigan Summer weather is not hot by standards of South or West but 90+ with high humidity does take the fun out of mowing or trimming so I have an
excuse for going into basement to work on a recent acquisition.
Not a Wizard but close enough, a Mercury KD3S (essentially a Wizard WD3S.) At time of purchase I had given it the once over noting probably condition and
the usual evidence of unskilled prior workmanship. It did turn over freely
and there were enough good parts showing to justify price. In other words
the price was right.
Tear down began with a small accident resulting in a pinched finger...OUCH!!!
Rest of tear down was routine...
1) disconnect fuel line & remove carburetor
2) remove fuel tank/rewind assembly
3) separate powerhead from leg
4) remove handle
Spent yesterday breaking powerhead into separate components for evaluation
for reuse or replacement.
a) cylinder scored...replace
b) piston scored and piston pin a little pitted...smooth piston and replace pin
with one in better shape that fits snugl
c) all crankshaft cartridge bearings look good will reuse
d) upper crankshaft seal bad lower seal probably good enough
e) crankshaft about as good as they come...clean up and reuse
f) magneto plate needs to be degreased...coil looks ok
g) upper rod bearing cartridge looks good to reuse
Today washed parts in Super Clean detergent to remove grime grease and loose
Tank appears fuel tight and cap assembly good.
Washed and scrubbed
Rewind assembly had been misassembled and several parts missing. For some reason the short key gets left out by most who try to work on rewind. A small
but vital part but one that is easily made...takes some filing,fitting and
patience as it takes time. Also tapped acorn nut and ran die over shaft thread as they were rough. Keyway needed a little TLC with file. Key stock
a tad oversize so that took a little more time with files.
The rewind spring is unlike any I have seen before but probably is correct
and can be reused (end loops are riveted so as to be closed.)
At this point I have a pile of parts that will need more prep to paint but
everything looks to have potential.
Leg and lower unit hanging on rack untouched at this point.
This little project is going along about as expected. If the coil is good
it should be a low cost rebuild into a runner. I do not expect the absent
carburetor and spark plug covers to show up.
Using a piston pin from another piston may seem like shoddy workmanship but
a) the original pin was suspect b) the replacement pin fitted into piston
with about the same pressure indicating the pin is a close fit. I am less
happy with piston but it should work ok. If I change my mind there are some
options in an incomplete powerhead project.
More to follow as project moves along.
Several go rounds with early Kiekhaefer singles and twins have made me aware of several things that apparently are easy to get wrong.
1) the two screws and lock washers that secure water pump to gear case are
unique to that purpose and location due to undersize of screw head and
lock washers. They will fit elsewhere but other screw heads and lock washer are too big to fit into water pump casting. This is an important detail to prevent water pump/gear case separation due to vibration in use.
2) the 6 screws fastening powerhead to leg are 3 different lengths...note
carefully the location for each pair. The variety of odd lengths of
1/4 x 20 fasteners used on these motors make it easy to get them confused.
3) the 5/16" screw securing gear case to leg may requires an under size
lock washer. If so that would explain pieces broken off water pump casting
at that point.
4) misplaced, lost of incorrect fasteners are fairly common so as found does
not mean as it left factory. It is more common to find an early K Model
with these issues than not. Fasteners of K Model era are not same as
modern fasteners. Correct replacements would most likely have to be sourced from parts motors. Use of correct fasteners is both a functional and visual issue to keep in mind before during and after restoration.
At times "correct" is not possible...I have used socket head cap screws to
secure cylinder/water jacket to crankcase.
KD3 lower unit dis assembly often produces surprises and challenges...this one was no different...removing pin that clamp saddle swings on proved only
a little difficult...it was tapped and inserted correctly so a few minutes
twisting and pulling and out it came. Next the copilot assembly and springs...
again no difficulty. This gained access to nut on rod attahed to gear case
which again came off easily...from there on things got sticky.
The water pump prop shaft assembly is attached to gear case with unique to
that location screws and lock washer...it should have anyway...one correct
screw and no lock washer...the other was an incorrect screw no lock washer.
When water pump was removed not a trace of grease in gear case. Drive shaft
stuck in pinion gear...clamped drive shaft in vice and used mallet and 3 in 1 oil to persuade them apart. Very little wear on splines but usual corrosion
in seal/bearing area...scrubbed off filth to access condition...usable.
The propeller nut was properly secured with a cotter pin and easily removed
but propeller would not come off...the cavity at base of propeller should have a rubber bushing held in by steel washer...installed in reverse order...after removing those parts I tapped end of propeller shaft with
mallet with no result. Some time back I had made a tool to deal with this
...a thin piece of hard steel with a hole bored in it and then sawed into two
halves...this tool fits into space between propeller and gear case so entire
assembly can be suspended by propeller...installed nut to protect threads
and placed in hydraulic press...got a little movement of prop shaft down thru
propeller...pressed prop shaft flush with bottom of cavity in propeller and then used a bolt to follow prop shaft thru propeller under force of press ram.
That got propeller off but left part of clutch in propeller and part
on prop shaft...used two screw drivers to pry clutch disc free and off
prop shaft exposing drive pin. Drive pin was steel and bent in "S" shape so
it took a little time and effort to get it out...(first remove the spring
that secures brass water pump cover) Taking care with two thin rods pry
out impeller drive hub and cover. Impeller of course was unusable...if it
had been good I would have immediately downed tools and rushed out to buy
a lottery ticket....worked prop shaft out of water pump housing.
Hint: grease prop shaft each season with marine grease (gear case grease.)
Bagged up all propeller related parts and set housing and gear case aside
for thorough cleaning which will include removal of spacer, spring and
seal from drive shaft entry to gear case.
Things went well even though several problems were encountered. This motor
has been apart at one time (perhaps 40 or more years ago) and probably has
seen little if any use since that "overhaul." Knowing what to do and how to
do it would have cost no more and taken only a little more time. I have seen
a number of similar less than skilled workmanship efforts on the Early K Model Kiekhaefer outboards. Restoring this little outboard to running condition will take only nominal investment except for a new impeller.
"Messed with before" projects are interesting insights into prior history
of an outboard. Someone thought enough of them to try. They either liked
working with their hands or had a purpose for a little old outboard. It is
unfortunate they lacked knowledge or were under pressure of time and lacked
resources. A little advice and encouragement might have led to a happier
Mercury KD3S project is coming along pretty well. Primed parts to be painted today. Painting soon probably tomorrow. It takes some time and effort to arrive a point where you can see the light at end of the tunnel.Once painted there is not a whole lot more to do to put it back together. In sorting fasteners the special screws and lock washers turned up so one less problem to solve.
This outboard motor obviously has not run in many years. I am hopeful it may
be in running order sooner rather than later.
Aluminum lacquer spray bomb paint is pretty easy and easy to touch up as needed
later on. Got the KD3S parts painted in a brigher aluminum than original dull aluminum but if you don't mind flash it is acceptable. I have a couple cans of dull aluminum with a hard to use spray valve cap so I went with easier to use/
Everything went well except I misplaced acorn nut for prop shaft. Looked and used magnet broom but no luck. I probably have another...somewhere.
Aside from that things went well and spray can did not run out until all parts
were done. Being as I try to make most gaskets from gasket stock assembly will
be a leisurely process. I will install bearings and a new top seal in crankcase...a matter of a few minutes with press. The water pump housing seal
usually is solidly in place requiring a bit of picking and prying to get it out usually in pieces. If there is an easy way I have not discovered it. I might just let it go for now given that the prop shaft isn't all that great. The more
I think about it the more that sounds like the way to go.
The Kiekhaefer made K Model singles can be very quick and easy projects especially if you have a few needed parts lying around. If there is anyone
working on either a single or twin at present I would like to hear your
comments and or complaints.
Paint on parts dried overnight so trial assembly time...some good news and some
not quite as good. Crankshaft turns over freely just by rotating the entire
powerhead...no binding or wobble...the screws do not fit into the water pump
housing...hex socket head screws will fit...so they will be used. The gear set
is iffy due to rust. No great difficulty apparent at this time. Will have more
to report as assembly proceeds.
Took a break today and went to a large well attended Aomci Meet at Constantine. Michigan. A three day event on far West side of state down near Indiana line.
Long trip there and back. I was to meet a friend to swap parts but he could not
attend. In looking around two parts motors came to light...a prewar KB1 and
a Wizard WD4S. I bought the KB1 but passed on the Wizard. Both were stuck. The KB1 had wrong tank and carburetor.The Wizard was RUFF. It is fairly easy to pick up prewar motors but the steel tanks have a low survival rate. I am usually open to a parts motor at a fair price. I also picked up a prop with
clutch assembly and a tank and rewind with a red ball grip...I was told it
was prewar Mercury. Best part of going to a meet is opportunity to shake
hands with all the usual suspects and meet a few new friends.
I just looked over the rewind and tank...it appears to be for a single cylinder
model with a new to me rewind starter...KB3S?
I do not know why I thought I had a KB1...id tag clearly indicates it is a KB3.
That changes it from a parts motor to a restoration project. Finding the rewind
makes it a doable. Spent today removing parts and putting them in separate
containers. Power head is stuck looks like get out the grease gun time again.
The thread at end of crankshaft will not accept a nut even after use of thread file. I have made a tool by sawing a slit in 7/16" x 20 nut which I will
wedge open so as to fit over thread down to base of thread then squeeze shut
while backing it off the crankshaft thread. I hope that will establish a
good stating point for thread. That is the plan.
That done will use flywheel puller to remove cast zinc flywheel.
Then the magneto assembly. If the miracle elixer PB Blaster lives up to its
billing piston and crankshaft should be free or maybe not, Grease gun
and adapter near at hand.
KB3 was 1941/42 top of the line rewind starter equipped premium model that also
had carburetor cowl and spark plug cover. Kiekhaefer Corp. made outboard
motors up until government regulation ordered halt to all nonessential
consumer goods. Mr. Kiekhaefer had to continue production as long as
possible to continue in business while awaiting a government contract
to make an engine in which he had heavily invested company capital.
KB3 crankshaft thread would not start a nut even after use of thread file.
It is a good idea to have a nut on crankshaft thread when using flywheel puller
to protect thread from damaged. Giving the situation a little thought an idea
came to mind...take a 7/16" x 20 nut, cut a slit in side with hacksaw and open
it up with wedge...the idea being to place nut down thread, squeeze nut on
thread and back it off to clean up thread and form a start.
When I used wedge the nut split in half. As it turns out that was even better
because I could place 2 halves on nut on crankshaft thread and clamp with
vise grip...after several passes the end has a weak starting point. Tomorrow
will try to start die to finish thread rework. Then to use flywheel puller.
Sometimes the path to where you want to go leads you hither and thither
before getting you to where you originally wanted to go.
On a second note the process of turning the split nut caused the cylinder
rise out of crankcase...piston still stuck but now rod cap screws can
be reached with screw driver and the piston can be pressed out of cylinder.
May be a good idea to apply heat to expand cylinder...I definitely do not
want to damage what may be a great piston nor to harm what is probably
a good aluminum connecting rod. Very gentle persuasion is called for
Everything sprayed again with PB Blaster...said to be great stuff...
if so it will have to earn its reputation on this motor.
Spent some time in basement trying to figure out how to pur rewind together
correctly...something is not right and manual applies to later green tank
version of Magnapull starter.
Currently I am actively working on a 1947 Mercury KD3S in the basement and a
1941 Mercury KB3 in garage. Today it was 97F in garage and a cooler much
less humid in basement so naturally I worked mostly on KB3 in garage...
despite best efforts piston is still stuck in cylinder and Wico flywheel
is still stuck on crankshaft. I did manage to work lower cover off to get
a look at crankshaft journal and connecting rod. For some reason I seldom
find as much corrosion on prewar crankshafts as on postwar crankshafts.
Down in the basement the rewind starter struggle continued. Finally took the
spring up to garage to heat and rebend loop. That went well. Returned to
basement and after a number of trials found the right number of turns to
preload starter tension. Fastened handle on cord and gave it a number of pulls
which seem to indicate A1
Gave myself the rest of the day off.
About the only things holding up KD3S now are gaskets and seals. A funny thing
about these singles is that both have the same new to me riveted loops on
ends of starter rewind springs. I decided to heat and bend after comparing
the two springs. Heating spring leaves it relatively soft and pliable so it
can be reshaped. In the future I will try tempering in an oil bath. I have several spare springs needing hooks on ends so maybe more to report later.
Progress report on 1941/42 Mercury KB3. Used grease gun technique to press
piston down cylinder until grease leaked. Went pretty easily so PB Blaster
may have done some good on cylinder wall. After considering options pounded
on piston with WOOD dowel thru spark plug opening...more in hope than conviction BUT it worked! Removed "G" clips and piston rings and pushed piston pin out and removed piston. Screwed a threaded brass cylinder on to chankshaft
with just a small gap between brass and flywheel so crankshaft could be pressed down thru the flywheel hub....a new to me and risky technique....all went well on first press and successive pressing as brass protector went down a little
I released press and turned the brass up the thread of crankshaft...after
about 3 repeats there was a LOUD bang. That could have meant bad news like
a crushed crankcase but I was lucky...the flywheel was loose and nothing was
Boxed up parts and set things away. I used up my quota of luck for today.
Words have their place but it would be easier to explain with a couple pictures Taking a stuck project motor apart can be a contest between haste and patience.
Experience has taught me patience ruins fewer parts. I have the advantage of
some Mercury Service Tools, some tools I have made and a few tools an expert
made for me. I have also had the advantage of expert advice and encouragement
from friends in outboard club. For me there is nothing as enjoyable as taking
apart an older Kiekhaefer that someone consigned to junk pile decades ago and
bringing it back to life. No two projects are exactly alike and some will turn out better than others. They are all fun.
Today hot and humid so downstairs was the place to be working on KD3S.
Note: tearing down and rebuilding two motors at same time is not a good idea
but temptation is hard to resist.
I got out gasket cutting tools, gasket stock and old gaskets to use as patterns
then cut enough gaskets to assemble both powerheads. Pretty much routine
and it went quickly. No news there.
Now the real news...it is not uncommon to find the lower end of drive shaft
seal surface pretty rough and/or the original seal either missing or in tatters. It is possible to use a metal case lip seal but if drive shaft is
rough or uneven seal is of little use. Granted the gear case is packed with
grease so not much sealing is required. I have given the subject some thought
and today with all the tools at hand and some leather scraps a few experiments were tried.
I used a 3/8 punch and a 7/8" punch which seem to be good fits
on 1/2" shaft in the 3/4" pocket. Free hand punching would not locate 3/8"
hole concentric to the 7/8" disk of leather. The idea was right but the execution left a lot to be desired. Then the little gray cells kicked in...
using a scrap of maple, a 3/8" rod and a washer with a 3/8" center hole
that was slightly less than 7/8" outside diameter a tool was made.
a) drilled hole in maple to accept 3/8" rod
b) inserted rod
c) punched 3/8" hole in leather scrap
d) placed scrap on 3/8" rod
e) placed washer on rod over leather
f) placed 7/8" punch over washer and punched out a leather seal
Essentially what I have made is a flat leather washer that takes on a
cup shape when in place under the spring. Cleaning up drive shaft
and applying JB Weld and sanding it smooth is next on agenda. There
probably is something better to use in this application but using what
is on hand is a time and money issue. I doubt motor will get enough
use to make wear an issue.
The drive shaft on Kiekhaefer's early K Models uses a spring to retain
leather washer and a spacer to compress spring and align the gear case
to drive shaft/exhaust housing. I have taken apart quite a number of early K Models both prewar and post war. It seems the rule that prewar motors have
less corrosion of both crank shaft and drive shaft. Why this is I have not
Sometimes the results you want come with results you do not want. In July 16
comments I described how I removed stubborn Wico cast zinc flywheel from crankshaft of KB3. Flywheel did come off and there was no apparent damage...
but now the rest of the story. Yesterday I worked on stubborn rod cap screws
finally they released their grip and rod was removed allowing crankshaft to
be taken out of crankcase. Powerhead now fully apart for cleanup. Crankshaft
as usual for a prewar motor was not deeply pitted. After polish with fine wet
or dry I did a trial assembly of crankcase, crankshaft and lower cover. To my
surprise the assembly locked up. I did not think it was the crankshaft as it
had turned freely before flywheel had been removed. Today a test fit with
a known good crankshaft also locked and the KB3 crankshaft fitted and turned freely in another crankcase. A careful examination of the crankcase of
KB3 revealed no crack,distortion or unevenness.
While the press did remove a very stubborn flywheel and the damage to crankcase
was not immediately apparent it did ruin the crankcase. Not a project ending
just a readjustment. Another project will have to give up its parts to make
the KB3 and another project move ahead. The unusable crankcase resulted from
wishful thinking and a short cut approach. Not the first time I have learned
the hard way.
Last few days have been both hot and humid by SE Michigan standards so a bit
of progress on both Mercury KD3S and KB3 to report.
Finished stripping down KB3 and figured out a way to use later pawls in
early starter rewind. All parts are pretty grimy so much cleaning ahead.
Honed replacement cylinder for KD3S, fitted rings and assembled powerhead.
The daylight at end of tunnel is getting brighter. This project will still
lack cowl and spark plug cover but only required 3 new rings a top crankshaft
seal and the block to leg gaskets (other gaskets were made from gasket stock)
Cleaning supplies and paint a given for an old merc. Other than misplacing prop nut nothing out of ordinary. It remains to be seen if coil is as good as it looks.New rings and hone resulted in solid compression.
KB3 project does not appear to have any unresolved problems except replacement powerhead did not get a full tear down.
May have to take another look inside as it may be called upon to run.
One new bit of knowledge...lower drive shaft leather seal is not hard to
make and look to be as good as original seal was when new.
If ANYONE is working on an Early Mercury K Model or has a toughie to work
on PLEASE feel free to join discussion. If there is any way another "Little
Old Merc" can be revived count me in.