To replace a motor, we must first determine the DIRECTION OF ROTATION and REQUIRED RPM.
If your pulley and flywheel are on top, you will need a motor with CCW rotation. If the pulley
and flywheel are "upside down", you will need a motor with CW rotation. Then we figure RPM.
To determine required RPM:
If your motor still runs but speed is inconsistent, we have the apparatus to measure RPM and
simply measure the RPM while the speed is correct. If your motor is dead, we designed the
BFM-1 Motor Simulator and RPM Gauge which makes this a one minute procedure,
Occasionally I prefer a mental challenge, and have devised this formula to figure required RPM:
1. Determine capstan diameter. The capstan is the vertical steel post to the right of the playback
head. It will be either .25 (large) or .18 (small). Multiply this value by 3.14 to arrive at your
CAPSTAN CIRCUMFERENCE. Note that a cassette capstan will be much smaller than above.
2. Divide 3.75 (or 1.875 for cassette) by CAPSTAN CIRCUMFERENCE, then multiply
that result by 60. This will be your CAPSTAN RPM.
3. Divide FLYWHEEL DIAMETER by MOTOR PULLEY DIAMETER. Call this result X.
4. Multiply CAPSTAN RPM by X. This is your REQUIRED MOTOR RPM.
In about 75% of cases, we should arrive at something very close to 2000, 2460 or 3000 RPM. The vast
majority of 8 track motors operate at 2000 RPM, but not all. Keep in mind that actual RPM will usually
be 30-40 RPM lower once motor is installed and loaded down by the drive mechanism. In most cases,
RPM is correct "as is", but it is possible that internal adjustment of the centrifugal switch is necessary.
To save time, we often substitute an adjustable speed, tachometer controlled motor which is adaptable
to almost any machine. A new motor is INCLUDED with all Ford, Mopar, AMC and Wollensak restorations
and is considered a quality upgrade - outside of our flat rates - on most other 8 track machines. Below
are pictures and descriptions of the motors stocked and installed ONLY by Barry's 8 Track Repair.
|8TMOT - 1
2000 RPM CW or CCW rotation with internal pulse generator
Diameter 1.75" Length 1.95" 12V, 50 mA
Matshushita part # MYF-15AF3
(21 in stock) $ 34.95
|8TMOT - 2
2460 RPM CCW rotation with Fast Forward
Diameter 1.62" Length 1.80" 12V, 100 mA
Unknown manufacturer, part # 440417N
(15 in stock) $ 24.95
|8TMOT - 3
2400 RPM CCW rotation
Diameter 1.59 Length 1.48 12V, 100 mA
Audiovox type M4 for home and car units, part # 279-04
(42 in stock) $ 24.95
|8TMOT - 5
3000 RPM CW rotation
Diameter 1.82 Length 1.90 12V, 50 mA with grooved pulley
(11 in stock) 39.95
|8TMOT - 6
2000 RPM CW rotation with Fast Forward Nippon part # NAM - 3A
Used in a few Lloyd's combos and Realistic standalone recording decks
(18 in stock) $ 44.95
|8TMOT - 7
2400 RPM CW rotation
Diameter 1.625 Length 1.50 12V, 80 mA Mitsumi M40A2-2S
(220 in stock) $ 24.95
|Tips for perfect speed tweaking - non technician version
1. First, look for a speed adjustment. Some better units with onboard speed adjustments are Pioneer,
Wollensak, and some of the classic Delco 8 track machines. They're usually not labeled, but are almost
always the control closest to the motor. It never hurts to "try and return" an internal control; in fact,
it cleans them and eliminates noise from an old, oxidized internal connection.
2. A tighter belt will slow down the motor, but place more wear on the motor and capstan bearings.
Cheaper manufacturers generally used a specific belt tension to set the speed.
3. A larger diameter motor pulley will speed the machine up. Wrapping layers of tape around a
pulley can increase its diameter in tiny increments. 8 track sensing foil works GREAT for this.
4. A larger diameter flywheel will slow the machine down. Tape can work here too. If the speed is terribly
fast, a small flat belt (typically about .022 inch thick) placed very evenly and centered around the flywheel
only will produce a large change in a very short time, then apply tape to fine tune to exact speed.
5. If you have access to a lathe, you can reduce the diameter of a pulley or flywheel using that.
6. Using a thicker belt will increase the speed; this applies to both flat and square type belts.
What NOT to do:
Never use a series resistor to slow down a motor; doing this will ruin the regulation causing wow and
flutter. But if you know how to construct a VOLTAGE DIVIDER using resistors, that might work.
Never attempt to reduce diameter by hand filing unless you have a runout gauge to check uniformity.
|8TMOT - 8
3000 RPM CCW rotation
Diameter 1.81 Length 1.80 12V Matsushita Part # MYT-11KF
(33 in stock) $ 24.95
|8TMOT - 9
3000 RPM CCW rotation
Diameter 1.53 Length 1.96 Matsushita Part # MYT-15MF
Has slightly more torque than 8TMOT- 8, otherwise similar
(315 in stock) $ 34.95
|All 8 track motors EXCEPT ADJUSTABLE SPEED have a shaft diameter of 2 mm (standard size)
|BARRY'S 8 TRACK REPAIR stocks more than 2000 NEW 8 track motors!
|To maintain my claim as the world's best-equipped 8 track repair facility, I have purchased the entire
known remaining world stock of new motors for 8 track machines. You won't find them anywhere else!
|The World's Only Shop With 1000's of NEW Motors
|4783 N. Glenrosa Circle
Prescott Valley, AZ 86314
|8T-MOT-AFC (adjustable speed)
This is the motor I most commonly use since it eliminates the hassles of
matching the speed to that of the old motor. Install it, fire up the machine,
adjust the speed and that's it ! Motor comes with its own hand-built
speed control board, with a 10-turn control for absolute speed precision.
This motor has been 100% successful in ALL Ford and Chrysler units
which use a FLAT belt. Some AMC units are not tall enough to allow
for the motor's length, in which case a round hole can be cut into the
housing for the excess length to protrude through about one inch. As
long as the unit can still be mounted in the dash, this will work fine.
PLEASE NOTE that on a few Chrysler models, the motor mounting tube
is BARELY large enough in diameter, and that the new motor must be
PRESSED in using at least a 10 ton shop press. Without a means of
pressing the new motor in, it cannot be installed without damaging it
and your machine must be sent in for me to perform this procedure.
Motor comes with pulley for FLAT belt; this pulley cannot be removed.
|Click on images for larger view
|This motor usually requires 3 holes to be drilled. Two holes to
mount the motor itself, and one hole to mount the speed board.
Comes with hardware, insulators and four spacer washers.
|$ 74.95 including shipping
|Find general mounting and wiring instructions for my adjustable speed motors by clicking HERE
|8T-MOT-AD (adjustable speed)
This is the motor I use to replace ALL DELCO using the DUAL GROOVE
pulley for SQUARE cross sectional belts. This motor does not come
with a pulley, and the old pulley must be transferred to the new motor,
OR I can install a suitable pulley before shipment for an extra 10.00.
With an original Delco motor, this pulley is pressed on at the factory. To
remove it requires the heat of a hand torch, then the pulley must be set
onto the shaft of the new motor before it cools and contracts in size.
Once the pulley is installed on the new motor shaft, IT CANNOT BE
REMOVED without damaging the motor. This is a somewhat delicate
task, and I highly recommend that you let me install a suitable pulley
even though it may not be at the exact same height as the original. A
machine using square belts can tolerate some misalignment, whereas
a flat belt will wander off the pulley unless the alignment is nearly perfect.
To save time and hassles, it's okay to convert any Delco
unit to a single FLAT belt by purchasing the motor ABOVE
this one as the narrow grooves in the flywheel present a
negligible difference in diameter with adjustable speed.
|74.95 including shipping
|This motor, without a pulley, works as a replacement in the RCA
AP-1 car record player. For most Delco 8 track players, you must
send in your old motor so I can transfer the original pulley to this
motor. This requires a blow torch, is potentially dangerous and
is not recommended for the buyer to perform this operation.
|Akai CR-83D Exact OEM Replacement
Easy to replace: Remove the rear panel and the rear brace for the
tape transport, and the 4 motor connections are right there. DO NOT
BENCH TEST THIS MOTOR BEFOREHAND, IT WILL BURN UP THE
WINDINGS DUE TO THEIR UNUSUAL INTERNAL CONNECTION. Just
install it to the original terminal strip. Comes with correct pulley.
These motors may have some styrofoam residue from being in their original
shipping cartons for decades; of course this does not affect performance.
This motor cannot be used with any machine except the Akai CR-83.
44.95 including shipping
Later Ford and Delco using SINGLE GROOVE
PULLEY ONLY Exact OEM Replacement
This motor comes with the correct pulley. It is
very important to confirm that your machine has
the type of pulley shown before purchasing;
otherwise the speed might not be correct
39.95 including shipping
For use ONLY
with the very
shown at right.
This transport was
used in countless
HOME units of
|The popular Mitsumi transport shown at right is just the basic transport, to which was added the manufacturer's choice of track
change assembly, any special switches or other features peculiar to the model they were manufacturing. The basic transport is
easily identified by the white plastic head mounting bracket (which is probably cracked by now) and the rotating white plastic hub
mounted to the top of the capstan. This hub has three or four "nubs" on top which, when a track change is called for, cause the
solenoid assembly to transfer the rotating action to the track change CAM (behind the head bracket) for one revolution.
When a track change is called for, the solenoid pulls down an arm which catches on a "nub" and thus transfers the motion of
the rotating hub to the cam which CAN rotate, but does not until activated by the transfer of motion. By the time the CAM has
rotated to the next track position, the solenoid has already released and will not transfer motion again until the next track change.
Replacing the motor and capstan on this transport can involve many steps depending on the individual machine. For this reason,
it is very important to take exhaustive step by step notes and draw pictures of everything you have removed for easier reassembly.
I DO NOT OFFER ANY ASSISTANCE ON THIS, BUT WILL SUBTRACT THE COST OF THE MOTOR FROM THE OVERALL JOB IF
THE MACHINE NEEDS TO BE SENT IN FOR CORRECT REASSEMBLY. MACHINES SENT WILL BE FULLY REPAIRED AT MY
STANDARD RATES FOR THAT TYPE OF MACHINE PLUS RETURN SHIPPING COST TO COVER THE TIME SPENT "RE-FIXING".
As the size of the capstan - flywheel might vary, including the NEW capstan is necessary to ensure correct speed with this motor.
These motors and capstans were removed from BRAND NEW, NEVER-INSTALLED complete tape transports and are pre-matched.
Motor and capstan pair ONLY: $ 34.95 including shipping
|Please note that I very seldom use the motors shown below, simply because it is so much
faster to use my adjustable speed motors without the hassles of fit and exact speed matching.
These motors were obviously made for "some" model of 8 track machine, but I really have no
idea which. As mentioned previously, what COUNTS is physical fit, RPM and rotation direction.
If I've seen a certain motor in a certain model, it will be mentioned in that motor's listing. DO
NOT ask me if a certain motor will work in a certain machine, because I won't know the answer.
As a convenience, I have devised a formula that will determine the required RPM of your 8 track
machine. From there, you can determine whether one of the motors below will work for you.
Note that motors can drift in speed slightly over time, and some measures might need to be
taken to get your player running at the exact correct speed. As a business who needs to turn
a profit and thus complete jobs in a timely manner, I can't afford to waste the time it might
take to get the exact speed dialed in and prefer to simply go with an adjustable speed motor.
All motors will be tested for actual RPM before shipment. Motors cannot be returned, and
no refunds or exchanges are possible unless the motor is found to be defective. If the motor
you purchased doesn't work for you, I will need to do the work myself at my normal rates,
MINUS what you paid for the motor, but PLUS my return shipping cost for the machine.
If your motor is currently still working, Harbor Freight makes a very handy and easy to use
handheld tachometer that reads actual RPM directly - their item number # 66632. Almost all
motors of this type have an internal centrifugal switch that can be adjusted to correct speed,
but this can easily turn into hours, even days since the motor must be completely taken apart
to make an adjustment, then fully reassembled and reinstalled in the machine to check speed.
Again, this might be an enjoyable project for the hobbyist who has plenty of free time, but it's
definitely not the way to go if you want to get your machine fixed quickly and be done with it.
So - for all you 8 track hobbyists who enjoy a challenge, here is the formula to determine what
RPM your machine requires to operate at the correct speed. Don't forget rotation direction !
If the belt is on top, you need CCW rotation. If belt is below, you will need CW rotation.
NOTE: My motors are NOT direct drop-in OEM replacements, they are what was still available 25
years after the LAST 8 track unit was offered by Radio Shack in their 1990 catalog. A HOBBYIST
CANNOT SUCCESSFULLY INSTALL MY ADJUSTABLE SPEED MOTORS, it requires the skill and
circuit knowledge of a PROFESSIONAL technician to wire it in (which sometimes requires
changes in the original circuitry), and often requires considerable metal fabrication skills and some
light machinery to mount it physically from my own experience. My metal fabrication skill comes
from 25 years in the HVAC field (concurrent with my electronic interests), where my daily task was
to adapt new furnaces to the existing ductwork by making the appropriate fittings and adapters.
When I sell a motor, I am selling a part to a customer who claims to be a professional level
technician and I'm also losing a repair job. Given these factors, there is ZERO TECH SUPPORT.
You are purchasing ONLY THE PART, NOT ONE MINUTE OF MY TIME OR KNOWLEDGE. IF
YOU HAVE TO ASK ME WHETHER A GIVEN MOTOR WILL WORK IN YOUR MACHINE, YOU
ARE NOT QUALIFIED TO INSTALL IT AND I WILL OFFER ONLY FULL SERVICE TO YOU.
Exact dimensions are given for my adjustable speed motors, and all it takes is a ruler to make
sure a motor will fit. For home units, you must know where you can tap into required voltages
and the motor requires roughly 500 mA - more than some machines can supply, and your best
bet might be to build a separate 12 volt supply for the motor. As far as integrating the new
motor with special functions like fast forward, pause and end-of-tape stop, that is entirely the
customer's responsibility and I am unable to offer ANY assistance whatsoever.
Again, you're buying a part, not my time or knowledge which is only available on PAYING
REPAIR JOBS. Selling motors is a courtesy I offer to those who can install it without any
involvement on my part. THE ONLY WAY TO ORDER A MOTOR IS TO ORDER ONE -
I WILL IGNORE ALL INQUIRIES ASKING WHETHER IT WILL WORK IN YOUR MACHINE.
|PLEASE NOTE that the motors shown below are purchased at CUSTOMER'S RISK, and that NO TECH SUPPORT is available.
|More than 200
|More than 200
|Approx. 50 in stock
|NOT USED IN ALL AUDIOVOX PLAYERS
|Seen in one or two Realistic models - sorry, forgot which
|E-mail Me at firstname.lastname@example.org or Just Click HERE
|DUE TO FINITE AVAILABLE REMAINING QUANTITIES, I AM RELEASING MY MOTORS ONLY
AS PART OF A PAYING REPAIR OR CONVERSION JOB AND CANNOT SELL THEM OUTRIGHT.
MY MOTORS ARE NOT DIRECT OEM REPLACEMENTS FOR THE MOST PART, REQUIRE
THE KNOWLEDGE OF A PROFESSIONAL TECHNICIAN AND OFTEN THE SKILLS AND
MACHINERY OF AN ADVANCED METAL FABRICATOR TO PROPERLY INSTALL. IT CAN'T
BE DONE BY THE LAYMAN, OR EVEN THE ADVANCED ELECTRONICS HOBBYIST.
PLEASE NOTE THAT MOTORS AND BELTS FOR 8 TRACK PLAYERS HAVE NOT BEEN
MADE IN DECADES AND ARE BECOMING VERY HARD TO FIND. I AM UNABLE TO
ASSIST THE DO-IT-YOURSELFER IN ANY WAY, AND I DO NOT ANSWER QUESTIONS
THAT BEGIN WITH "DO YOU KNOW WHO..." OR "DO YOU KNOW WHERE..."
I AM HERE TO REPAIR YOUR MACHINE - I AM NOT A PARTS SUPPLY HOUSE, A SOURCE
FOR FREE REPAIR ADVICE, OR A BROKER TO HELP YOU FIND A CERTAIN MODEL.