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
|Now Selling 8 Track Motors For the Do-it-Yourselfer
|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.
|$ 64.95 including shipping
|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.
|64.95 including shipping
|NOTE: If your Delco machine already has a BOARD MOUNTED
speed adjustment, you won't need the extra speed control board
and can subtract $15 from the price. All units that used the "fat"
2 inch diameter motor WILL require the extra speed control board.
as the speed adjustment was originally on the motor itself.
|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.
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
|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.
|I DON'T SELL BELTS - PLEASE DO NOT CONTACT ME TO PURCHASE BELTS !
For belts, please visit my friend Frank at www.studiosoundelectronics.com
|The ONLY items I sell are on this page - please DO NOT ask me about any other parts.
Among the hundreds of different 8 track motors that were once used, only a scant few of them remain. To eliminate the
extreme hassles of matching a motor to the machines it will work in, I have developed a special ADJUSTABLE SPEED
motor that will work in ANY machine as long as it will fit physically. My adjustable speed motors are much more expensive
as they require me to hand-build a special speed control board, but the amount of time and frustration they save is worth it.
PART NUMBERS ARE USELESS. There is no such thing as a master cross reference guide for 8 track motors, making
their part numbers a meaningless stream of numbers and letters. What counts is whether the motor will fit physically, its
direction of rotation and its RPM rating. Since my adjustable speed motors can be adjusted to any required RPM and can
be wired for either CW or CCW rotation, the only information we still need is whether there is sufficient CLEARANCE.
Please note that in almost all cases, my new motors will require drilling 3 holes: Two holes to mount the motor, and one
hole to mount the speed control board. The installer may also need to insert shims or spacer washers in order to make
the pulley align properly with the capstan / flywheel. Machines using SQUARE belts can tolerate a considerable amount
of misalignment, but a machine using a FLAT belt is much less forgiving and alignment is much more critical.
The purchase of one of my ADJUSTABLE SPEED MOTORS includes E-MAIL TECH SUPPORT ONLY. There is
nothing I can do to help you over the phone - but if you send me pictures of the inside of your unit, I will add arrows and
captions describing how to mount and wire your new motor. THIS APPLIES ONLY TO MY ADJUSTABLE SPEED MOTORS.
To make sure my adjustable speed motor will work in your machine, it is only necessary
to measure for physical clearance. My adjustable speed motors are longer than many of
the originals, and the motor's full dimensions are shown in its listing.
Please note that my tech support covers MOTOR MOUNTING ONLY. It does not cover
any machine disassembly required to ACCESS the motor. Thus, it is very important
to take diligent notes on every step of the disassembly process, so that you can simply
reverse the procedures in order to put your machine back together. If you don't feel
comfortable and capable replacing your motor, it's best to pay me for machine service.
To order a motor, first make sure it will physically fit. If it will fit, we can make it work.
Then, call me at 928-533-9666 to pay with a credit card. If you have any questions about
fit or function before purchase, PLEASE include pictures of the inside of your machine.
If your machine has Fast Forward, a little extra work is needed to preserve this function.
As time permits, I will be putting pictures of suggested mounting schemes on this page.
Until then, I am happy to walk you through the replacement process via E-MAIL ONLY.
Requires only basic soldering skills - I take care of all critical and fine soldering beforehand.
Most motor mounting is simply drilling a few holes and installing spacers for alignment. In
rare cases, you may need me to fabricate a new mounting platform for an extra $20.
Feel free to ask any questions before ordering a new motor.
|PLEASE NOTE that the motors shown below are purchased at CUSTOMER'S RISK, and that NO TECH SUPPORT is available.
|( Don't waste your time looking for any of these motors elsewhere; I have already purchased all that were available in 10+ quantity )
|Approx. 450 in stock
|Approx. 350 in stock
|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