Gas Engine Magazine

Fuel Pumping System and Oiler Repair

By Staff

I took a look at the camshaft arrangement for
the pumps. There are two ratchet assemblies, one mounted on the
fuel tank. This ratchet has a camshaft mounted on top that stops in
four positions. The second ratchet is mounted on the rear end of
the transfer port cover. It is spring-loaded, with a wedge-shaped
tooth that engages a spider wheel on the camshaft. It ensures that
the camshaft reel turns only in one direction. The camshaft reel
itself has three sets of camshafts: two having four lug-type
camshafts set 90 degrees apart, and each camshaft set itself was 45
degrees from its neighbor. The third set is the spider wheel, which
has eight angular lugs that engaged both timing ratchets at various
times. As the crankshaft turns, the ratchet assembly, when engaged,
advances the camshaft assembly at the rate set by the adjustable
ratchet. This can be from no movement of the camshaft, 1/8 turn,
1/4 turn and to approximately 1/3 turn. Each setting provides a
different camshaft action on the pumps.

“I was astounded to find the bugger (the flywheel)
weighed 351 pounds with the governor attached!”

On the first setting, with no movement, the setting maintains a
simple stroke of the camshaft, maintaining the pump selected,
whether it be on the primary or secondary pump. On the 1/8 turn
setting, the camshaft is allowed to trigger both pumps on an
alternating basis. For each revolution of the crankshaft, one pump
or the other is triggered. I should note here that the secondary
pump has the provision to alter the stroke of the pump itself by
means of a threaded camshaft pushpin and jamb nut – for adjustment
of stroke as required by the use of different fuels.

For the third setting, the position allows the camshaft to
advance 1/4 turn, activating the pump selected at every revolution
of the crankshaft. I believe this position is a set up position for
the fourth setting. This last setting is triggered on the primary
pump injection stroke only. The 1/3 turn allows the primary
injector pump to be triggered only every other revolution of the
crank. The engine double-strokes during this setting. If the engine
were to be run constantly, and have long periods of no load, speed
could be maintained during the no-load cycle with this setting at
the savings of half the fuel normally used.

The entire camshaft assembly is mounted on a rocker arm,
activated off an eccentric camshaft on the governor side flywheel.
With the governor at rest, this eccentric has maximum throw, about
1-inch total, which translates to about 2-1/2 inches of throw at
the fuel end of the camshaft assembly. As the engine speed
increases, the eccentric is spun in its axis and at full-governed
speed, the eccentric barely moves the rocker arm. The ratchet
assemblies turn the camshaft assembly no matter what the rocker
stroke may be, but the length of stroke the camshafts give to the
fuel pumps may vary from nearly 1-1/2 inches down to no movement of
the pump drive pistons at all.

The rocker also has a pivot pin opposite the camshaft assembly
that drives the oiler. As engine speed increases, the pump stroke
is shortened, maintaining a constant flow of oil to the piston and
its bearings, but cutting back on volume as the load lightens.
Luckily, the fuel camshaft assembly and both ratchet assemblies
were not stuck. The governor was free as well, and only needed a
cleaning and oiling. I did have to remove the governor side
flywheel though, so I could place some needed thrust washers on
several shafts to take out end thrust that was excessive.

When the engine was built, these shafts had virtually no
clearances with the governor’s rotating assembly and the linkages
must have been a pain to maintain. I weighed the flywheel while it
was off the crank, as it seemed to be unusually heavy for its size.
I was astounded to find the bugger weighed 351 pounds with the
governor attached! Guessing that the governor itself weighs around
25 or 26 pounds that still leaves 325 for the wheel itself. I
cleaned out and repacked the well for the governor camshaft with
cotton clothes drier lint, as the original material had rotted away
long ago. I was getting tired and it was after 10 p.m. so I called
it quits for the night – outside that is.

Though my first attempt to post questions at
resulted in no information, I wrote once again about the
Charter-Mietz and the Madison-Kipp oiler. This time I was more
successful. Dusty Erickson from Arizona replied to my query and
stated that the engine was related to the Mietz & Weiss Engine
Co. of New York. As it turns out, Dusty has even written a book,
Mietz & Weiss, New York, America’s First Successful Oil Engine,
based on his research and the company itself. I learned a lot of
information about the operation of my engine as well as some things
that did not seem to be in the norm in comparison with other
Charter-Mietz engines known to exist.

Dusty also gave me the name of another Mietz & Weiss
enthusiast, Fred Prichard, of New Hampshire. Fred noted several
items as well on my engine that did not meet the norm, and after
consulting others I came to the conclusion that my engine was
unique in itself. No one had seen another Mietz & Weiss or
Charter-Mietz set up quite like it. The general consensus was that
either the engine was a factory prototype, not put into production,
or that the engine was a college teaching engine, used as an
educational tool. It would have been set up with changeable
features and accessories in order to be able to run the engine with
these changes and compare the results.

Fred also led me to another person who helped tremendously with
the Madison-Kipp oiler. Dave Preuhs of Minnesota has a website
dedicated to Hart-Parr tractors. Within the website, he also has a
section devoted strictly to the Madison-Kipp lubricators. Hart-Parr
used two versions of the Model 50 on their tractors and their
internal parts were compatible with mine. Dave also rebuilds these
lubricators and can obtain parts, although parts are getting scarce
and more expensive because most of them are no longer being made.
The lubricator section of Dave’s site has a parts breakdown and an
exploded view of each pump assembly (of which there are four in my

The oiler

The outside of the oiler was only a little rusty, covered in oil
and flaking gray paint, with a gloss black paint underneath. The
case on the inside, the case interior and internal parts were not
rusty either. The oiler case was half full of clean, clear water.
This was due to the fact that the oiler drip rate sight glass had
been broken a long time ago and the oiler case had filled with
water. The ice formed when the oiler got cold, broke the sight
glass and allowed any future water to seep out through the cracks
in the glass. Three of the four oil lines were badly crimped and
the fourth had been broken off at the fittings and was missing.
Inside the case, all was not pristine either. After the original
removal from the engine, I had sprayed the top of the unit with a
load of WD-40. I again loaded the top with WD-40 and proceeded to
clean all the crud off the case with a stiff bristle engine parts
cleaning brush. When I was done removing all the built-up junk, I
found the builder’s plate in excellent condition! It reads:

Madison, Wis. U.S.A.
Model 50 Sight Feed
Pat. July 1, 1926 – Apr 10, 1918

The oiler identification plate is made of zinc, and the fact
that it is even intact is somewhat of a miracle. The first hint of
what I was to find inside was on the outside of the unit. The four
zinc oil sight cups were all heavily damaged. There was not one
that I could salvage; two of them were nearly totally eroded away.
I tested the four oil rate adjusters and found two of them bound
just as tight as the main shaft in the unit. This did not bode
well. In the instructions from Dave’s website, it clearly said, “Do
NOT force the crank to turn, if the unit is stuck – severe damage
could result!” The way this thing was stuck, I don’t think my
2-foot pipe wrench could have turned that shaft!

I then removed all the screws from the top of the cover and
tried to remove it. No such luck. I tried heating the adjusters,
putting Liquid Wrench on them, hitting the cover with a plastic
mallet and plain old prying. Just staring at it produced no results
either. I finally got the top loose with a combination of

First I removed the crank handle and the pivot arm from both
ends of the oiler. Then the shaft end bearings were removed, which
provided some movement in the top itself, but not much. I hosed
down the interior with WD-40 and some automatic transmission fluid
from a squirt oil can and left the unit upside down for the next
few days. I tried everything again and the top still would not
budge. I was beginning to get a little steamed, so I took two big
Craftsman flat blade screw drivers and hammered them between the
top of the unit and the case. I could see where two of the
adjusters were pulling on the top of the unit.

I tapped all of the adjusters with a small steel ball peen
hammer and after the second round of spraying and hitting, the top
popped off with a loud snap. The last two adjusters finally let go
of the shafts on the oil injector pumps.

With the top off, I could see what I was getting into – it was
not pretty. Each individual pump has a two-piece cam-eccentric
mounted on the pump drive shaft. These in turn connect to a
connecting rod with a small shaft mounted to one side.

This assembly is actually a dual piston assembly that works in
the following manner: The cam-eccentric imparts two separate
actions to each pump. The first action is a simple camshaft action.
It raises and lowers the main pumping mechanism of the individual
pump. The second action is that the camshaft design makes it wobble
on the shaft center. This wobble imparts a twisting motion to the
pump piston. The piston itself has cuts made in it and depending
where these cuts align, the flow of oil can be regulated. That
alignment is the function of the adjuster heads that are protruding
through the top of the oiler. That is, they move the cylinder
intake, which in turn regulates how much oil flows through the pump
mechanism. The first motion brings oil up through the oiler sight
tube. After the oil drips through the sight area, it is then forced
into the engine by the second piston. In trying to turn the crank
handle, I found that the number two pump cam-eccentric was the only
item that was free, besides the shaft ratchet pivot.

I tried everything to free the shaft and the cam-eccentrics. As
it turned out, the whole effort was an exercise in futility. Over
the next three days, I tried everything to get the camshafts to
move, with no luck. I tried heat (lots of it), WD-40, Kroil and
Liquid Wrench, all to no avail. I finally decided that to
effectively get the pumps out, I would have to remove them as an

I removed the oil supply fittings and the bolts that actually
mount the pumps, and then tried to remove the whole works out the
top of the oiler. The pumps came loose OK, but I still could not
remove them. In fact, I now found that the camshafts were loose on
the shaft, but were actually stuck in the connecting rod bores on
three of the pumps. The problem now, was trying to get the shaft
out of the pump case. It turned out what I thought was a single
shaft through the unit was actually a two-piece shaft: one side
driven by the engine governor pivoting shaft, relay rod, a ratchet
wheel and pivot pawl assembly, and the other independently turned
either by the ratchet wheel or by the external crank handle,
mounted on the opposite side from the governor drive.

The two sections are linked through a brass keyed fitting, which
is driven either by the engine link or the handle, and this in turn
is held in place by a tapered steel pin. When the oiler stopped and
seized, the pin was at right angles to the top of the oiler and I
could not drive it out. As it was though, I could rotate the shafts
about 1/8 turn due to the play in all the loose assemblies within
the case. After three days of struggling, all I had to show for it
was a bunch of cut fingers and a box full of loose parts and broken
glass from the long gone sight-feed. To make matters more
complicated and frustrating, the ratchet wheel pawl would fall out
of position and jam the entire assembly to one side. Usually when
this happened, the pawl spring would fall out of its recess and end
up in the bottom of the oiler case. Getting it freed was a real

Finally, the pawl fell out and jammed the shafts so tight I was
going to take a hammer to it. As I was looking at the case with a
real glare, hammer in hand, I noticed that the tapered pin was in a
position where I could get a small pair of channel lock pliers on
the small end and on the outer surface of the ratchet wheel at the
same time, giving me an opportunity to pop the pin loose and to
remove the hand crank-driven shaft from the unit. This was done in
nothing flat, and much to my surprise when the hand-crank shaft was
pulled out, the entire interior mechanism fell to pieces. I finally
had the oiler disassembled.

Almost. As I was looking at the pumps and the zinc castings, I
found out why the cam-eccentrics did not come free from the
connecting rods or each other. When immersed in the water, the zinc
became a sacrificial metal. That is, it was destroyed instead of
the iron parts under water. This galvanic action made the zinc
swell and split, seizing it in the connecting rod bores. The pumps
themselves had also seized, rendering them useless. I contacted
Dave and he told me he could get replacement cam-eccentrics, but
they were $40 to $60 per half and I needed eight halves! Dave
rebuilds MK oilers for a modest price, but he said it sounded like
a replacement was more warranted than a rebuild in my case, due to
the damage. Dave recommended I try eBay, and after five different
auctions I finally won a new oiler.

The fuel pumps

I went to work on the fuel pumps and their piping. Both Fred and
Dusty told me that the left-hand pump was the original primary pump
for the M&W as well as the Charter-Mietz engines. Although the
pump piston was stuck, the pump seemed to be in fair condition. The
first objective was to remove the check valves and the primary fuel
injector piping from the pump. The check assemblies are marked
suction and pressure. On both pumps, the SUC checks were mounted to
the rear of the pump and the PRE checks were on the front. The
check valves were also full of crud and the primary pump also had
water in it, due to a broken off fuel line. The primary pump piston
was a pain to remove as well.

First, the packing gland nut was loosened. The pump return
spring was compressed and that made working on the pump even more
difficult. There was no packing under the gland anyway. The pump
was then removed from the engine and the body was placed in a vice.
A small slide hammer soon had the pump piston out and it was
cleaned on a bench-mounted power wire brush. The pump housing
needed a thorough cleaning on the inside as well because it was
full of sludge. I did not clean the exterior of the pump very much,
as there were rust spots on the paint that was on it. The pump was
reassembled with new packing and the pump was remounted on the pump
mount plate. The secondary pump just needed a tap on the pump shaft
to free it. It was missing the discharge check and all piping.

The fuel injector nozzle was cleaned, as well as the injector
housing and a new supply pipe was made from a piece of 1/4-inch
copper tubing. The supply line goes from the fuel valve to the pump
inlet check. The valve on the tank had three connection openings
available: one was marked gas (on the side, capped) and the other
was marked kero (on the fuel tank side). The third connection was a
compression fitting for connection at the inlet side. This consists
of a ground-in ball and socket fitting that is soldered to the fuel
line, and a lock nut that butts the ball end of the adapter into
the socket in the check valve. The fuel tank supply line had been
wrung off and I had to remove the old snapped piping and install a
new one. I heated the soldered fitting, grasped what was left of
the copper pipe and gently twisted. Once heated, it slipped out of
the brass fitting easily. I noted the original solder joint was not
well done and I needed to clean out the oil brass fitting.

I taped 100-grit emery paper to a 1/8-inch drill bit with a
piece of duct tape. I then inserted it into the brass fitting and
spun it with the drill for several seconds. I then inspected the
brass and it was clean and shiny on the inside. I made a new copper
fuel line, and after a trial fitting and several adjustments,
soldered the line to the fitting and then made the compression
fitting on the tank valve.

This done, I put kerosene in the fuel tank and worked the fuel
pump lever quite a few times. I could hear the injector working
after a few strokes of the primer lever. I also saw some kerosene
leaking from the pump packing. I tightened the packing gland nut
and quit for the night.

Since I’d bought parts from Ed Deis from Hit & Miss Engines
in the past, I thought I’d give him another try. They had a
two-post unit, free – not stuck, but in unknown internal condition.
It cost $75. I received this oiler and the other I won off eBay on
the same day. Both units were pretty grungy, covered in grease and
grime. I hosed both of them down with Gunk Engine Brite engine
cleaner and scrubbed them with the bristle brush I used on the
original oiler from the engine. I then hosed them off with water
and kerosene and proceeded to disassemble both units. They each
took a day to take apart and luckily the internal parts in both
were in good shape. I ordered several parts from David, including
the glass hood for the four-post top, the replacement for the keyed
spacer and a gasket for the pump mounting flanges.

Putting the oiler back together was a real chore. The pumps had
to be reassembled, and the camshaft halves installed into their
respective connecting rods. The adjuster rods also had to be placed
in their bores and the entire pump assembly mounted on the hand
crankshaft. This procedure must be repeated four times and as each
pump is installed on the shaft, the camshaft assemblies must be
aligned so the timing camshafts engage each other. The only problem
is that each time you pick up the shaft to install the next pump
set up, the others fall apart. After several attempts, I got smart
and put rubber bands around everything that could move, and finally
I was ready to put the assembly into the case.

The next issue was installing the engine drive shaft and the
ratchet wheel assembly into the case, and hooking it into the pump
drive shaft work assembly. As with the disassembly, the ratchet
wheel pawl provided the most trouble. Trying to get the ratchet
wheel, the pawl, its spring, the two shafts, all the pump timing
keys and the tapered pin mount holes to align was nearly impossible
to do by myself. I enlisted the help of my two sons, Richard and

At this time, I made one change to the internal working to the
lubricator mechanism. I changed out the original ratchet wheel with
one from one of the two units I had bought. The replacement wheel
fit perfectly, the only difference being that it had more teeth on
it than the one from the original oiler unit. This gives the oiler
a better flow control rate than the old wheel could give. After
about an hour of trying to align everything, we finally succeeded
in installing the pin, completing this section of the repair. It
remained to mount the pump bases to the case with the gasket,
install the top, sight glass and other various items.

Oiler assembly

I installed the needed spacer and the shaft end supports. The
engine drive side end support was severely worn. The bronze bushing
the shaft rides on was nearly cut through with wear. I reasoned
that this was one of the causes that there was so much damage to
the zinc parts inside the oiler. Besides the galvanic action
between parts, there was also physical wear, due to the fact that
the bushings were worn out so badly. In fact, while I was looking
the packing nut over, I noticed it looked like it had been hammered
on and the threads were stripped out on the gland nut.

I decided to replace it with one of the units I had bought. As
it turned out, only one of the four packing glands used was like
mine on the governor drive side because it had an adjustment on the
inside to take out thrust on the internal works. The other three
were fixed bushings, with an external packing gland only. I
replaced both supports with those from the H&M oiler, as they
were hardly worn.

The next step was to mount the oil pumps within the case. The
pumps are secured with a 5/16-inch fine thread bolt and the oil
supply fitting at the base of the pump that has a lock nut on the
1/8-inch pipe threads. Each pump must be aligned horizontally and
vertically. This is necessary to align the pump drive eccentrics
without binding. What made it even more complicated is that the
gasket for the four pumps was a one-piece affair. I had to keep
loosening the pumps already installed in order to install the next

Finally, after all four pumps are mounted into the case, you
have to snug up the bolts, then install the outflow adapters,
tighten the bolts and then snug the adapter lock nuts, after you
turn the adapter to match the oil line direction. Thankfully, all
four of the oil lines face straight down as they leave the oiler.
After everything was aligned, all connections were tightened. Once
I had all the pumps locked in position, I installed the hand crank
and attempted to turn the handle. It wouldn’t budge. I then gave
everything inside the case a liberal coating of SAE 30 oil, backed
off the endplay adjuster inside the case a little bit and again
attempted to turn the crank. This time it turned smoothly with the
ratchet wheel pawl making a genteel click, click, click as it

I locked the adjuster lock nut and went to work on the top for
the original oiler. I had to wire brush the top in order to remove
the old paint and some rust. I also had to free two of the four oil
pump adjuster knobs, as they were frozen in place. This done, I
installed the top temporarily and prepared to paint the oiler

Painting the oiler

I put some grease on the pump drive shafts, the oil pump sight
feeds and the zinc receivers. I also put some grease on the zinc
oiler identification plate and the hand crank to protect them from
over spray. I then taped off the exterior of the case around the
oil level sight gauge mount and painted the gauge area with Krylon
Chrome Silver paint, as it was originally silver. I stuffed the oil
level sight area with paper napkins and painted the entire oiler
with two coats of Krylon glossy black paint. I removed all the
grease with a rag soaked in kerosene.

Next, I assembled the oiler level gauge glass from the H&M
oiler into the engine oiler because it was in better shape than the
one from eBay. I bought new gaskets for the glass gauge from Lee
Pedersen, as well as a roll of gasket material, as the gasket for
the oiler sight feed glass was no longer available and I had to
make one.

When the gauge glass was secure in its mount, the oiler top was
ready to be installed. I salvaged new screws for the oiler top
mounting from the other two oilers and I polished them on my bench
polisher. I also polished the screws for the sight feed glass. I
had to salvage these screws, as all but one of the originals were
lost long ago when the glass was broken out. I had to salvage the
glass retainers as well as the screws. Between the two oilers,
there were just enough screws and retainers. (By the way, if anyone
needs the sight feed glass for a two-feed Madison-Kipp oiler, I
have two.)

I then mounted the oiler top onto the case. Mounting the top
presented two problems: One was that the sight feeds and the catch
cups have to be bent into position after the pumps are mounted.
They must not hit the case top, as movement within the case and
engine vibration will cause the zinc castings to fail. The other
problem is also related to the first. That is, the oil feed
adjusters are a slip fit into the adjustment caps that are mounted
on the top. Trying to get all four aligned was a real task.

Once I got the top mounted, making a new gasket and mounting the
sight feed glass seemed easy. All that remained to do now was to
mount the oiler on the engine, make the oil supply piping to their
delivery points, install the oiler pump drive arm and linkage to
the governor drive arm, and make final oiler adjustments.

Remounting the MK oiler was the easiest part of the whole job.
Putting on the two forged steel brackets was a matter of installing
two bolts and two nuts. Getting the oiler drive arm adjusted was
not so simple. The first thing I had to do was establish the center
of throw of the drive camshaft on the engine. I removed the
compression release valve and cleaned it – it is made of brass.
Removing the valve altogether made it easier to roll the engine
through the compression stroke. I rolled the engine through three
or four revolutions and noted where the camshaft stopped and
reversed direction at each end of its throw. I turned the engine so
that the oiler drive pin on the camshaft drive was at mid-stroke.
Then, I moved the MK oiler through a complete throw of the driven
arm and also made a note of where the center of the oiler’s stroke

With the oiler set at mid-stroke, I mounted the oiler drive arm
relay rod on the camshaft drive pin and holding the MK driven shaft
still, I tightened the drive arm in position with the relay rod
attached. This positioning put both the oiler and the engine
camshaft assembly at mid-stroke. When the engine was turned over, I
heard the ratchet wheel click twice. I turned the engine to top
center and turned it through a full revolution. Again I heard two
clicks, as the engine was on the compression stroke. As the
camshaft cycled, I noted it was not clicking for quite a while, as
the rod was drawn toward the engine. I figured the ratchet wheel
must have been near the trip point when the road stopped retreating
and I was not getting the full amount of shaft rotation that was
available. Adjusting the relay rod became a real time consumer, as
the ratchet off points seemed to change with each turn of the

Finally, I stopped for a break and glanced at the governor
spring. Then it hit me! As the engine crank was turning, the play
in the governor spring was allowing the governor to change the
stroke of the camshaft as I worked. I did not have a constant point
of reference to set up the oiler. I then re-set the governor spring
to take out the play and then re-set the camshaft pin-oiler drive
arm relation so as to get three clicks on the ratchet at every
engine revolution. This gave the oiler one revolution of the oiler
shaft to approximately 30 turns of the crankshaft. Later on, when
the engine was running, it turned out to equal one revolution of
the oiler to every 6 seconds with the engine at speed.

The MK oiler feeds four points on the engine from right to left
on the oiler itself. The first position feeds the right side main
bearing; the next, center right, feeds the piston and wrist pin
through the transfer port cover. The third position, center left,
feeds the left main bearing and the fourth, left side feeds the
connecting rod through a slinger – gravity tube pick up on the left
side bearing plate. The recommended oil is SAE-50 non-detergent
oil. As of now, this oil is not available in my area, so I am using
SAE-50 racing oil. I made up a new piston feed oil line, as the
original was missing, and straightened the other three lines. I
made up all the compression fittings and put new ferrules on the
replaced line, thus reusing the old fittings.

I should note that most of the pipe fittings were standard
National Pipe Thread (NPT) with the exception of the fuel system.
Although I had asked Dusty if the threads were of a standard nature
on the Mietz & Weiss engines (and he assured me they were
standard, nothing special) I did find an anomaly on the
Charter-Mietz: the threads per inch were the same, but the taper of
the threading was about one-half of the NPT thread. The thread was
a so much more shallow tapered that the fitting threads were about
1-inch long on the check valves instead of about 3/8-inch on a
standard 1/4-inch NPT nipple.

When I was done with the oiler piping, I went to my local NAPA
auto parts store and asked for their required SAE-50 oil. I bought
two quarts at $3.29 per quart. This put the oil about two-thirds of
the way up the oil level gauge, so I gave it a few turns. There was
only a little resistance to turning and there was no oil flow. I
then opened the oil adjusters all the way open and then again
turned the hand crank. After about 20 turns, the oiler was primed
and pumping oil into the bearings. Another milestone reached. I
reset the oiler drip rate to one drip per revolution for each of
the four posts and then figured I was ready to try and start the

Tune in next issue for part three covering startup, the cooling
system and the first shows.

Contact engine enthusiast Andrew Mackey at: 26 Mott Place,
Rockaway, NJ 07866.

  • Published on Aug 1, 2006
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