This is first Mercury K&O produced. Although it’s the first Mercury offered, this is not a rare motor. There is a version of this motor with top-mounted cowl screws that is VERY rare and valuable. The more common version with front and rear facing screws is fairly common and not as valuable. Many collectors consider the entire K&O Mercury line of motors yo be more desirable and valuable than other same-year K&O brands. No K&O Mercury’s were made with knurled wires nuts as seen on the OMC motors. All K&O Mercury years came with attached battery wires and terminals.

Notable Traits:

Height: 5.5 inches

“Japan” in raised letters under cowl tray towards rear

Wide chrome faceplate - later models had narrow painted faceplates

First year production year for Mercury

Bright green battery wires with red and blue insulators

Only year for the “Airplane” Mercury decal

Solid driveshaft between motor and propshaft

2-Blade Prop

Offered in brown box with black Mercury graphics

Came with instruction sheet, white plastic stand and metal battery post terminals

3 to 6 Volts

Rarity: 2.5/5 (Screw holes in top of cowl version rarity: 4/5)
Desirability: 3/5 (Screw holes in top of cowl version desirability: 4.5/5)
Value: 3/5 (Screw holes in top of cowl version value: 4/5)

*Ratings based on 1-5 with 1 being least and 5 being most

The first of three different paint combinations available, the green and silver version is the second most rare 1956 K&O Mercury. Model year updates are the “arrow” Mercury logo, two cavitation fins, and a painted narrowed faceplate. All three 1956 Mercury motors are rarer than the 1955 but, they are not considered a rare motor.

Notable Traits:

Height: 5.5 inches

Green and silver version – second rarest of the three available color combinations offered in 1956

“Japan” in raised letters under cowl tray towards rear

First production year offering multiple color combination Mercury’s

Bright green battery wires with red and blue insulators

“Arrow” Mercury decal

Solid driveshaft between motor and propshaft

2-Blade Prop

Offered in same brown box with black Mercury graphics as the 1955 model

Came with instruction sheet, white plastic stand and metal battery post terminals

3 to 6 Volts

Rarity: 2.5/5
Desirability: 3.5/5
Value: 3/5

*Ratings based on 1-5 with 1 being least and 5 being most

The second of three different paint combinations available, the green and sand version is the rarest 1956 K&O Mercury. Model year updates are “arrow” Mercury logo, two cavitation fins, and a painted narrowed faceplate. All three 1956 Mercury motors are rarer than the 1955 but, they are not considered a rare motor.

Notable Traits:

Height: 5.5 inches

Green and sand version – rarest of the three available color combinations offered in 1956

“Japan” in raised letters under cowl tray towards rear

First production year offering multiple color combination Mercury’s

Bright green battery wires with red and blue insulators

“Arrow” Mercury decal

Solid driveshaft between motor and propshaft

2-Blade Prop

Offered in same plain brown box with black Mercury graphics same as the 1955 model

Came with instruction sheet, white plastic stand and metal battery post terminals

3 to 6 Volts

Rarity: 3/5
Desirability: 3.5/5
Value: 3.5/5

*Ratings based on 1-5 with 1 being least and 5 being most

The third of three different paint combinations available, the red (sunset orange) and sand version is the most common 1956 K&O Mercury. Model year updates are “arrow” Mercury logo, two cavitation fins, and a painted narrowed faceplate. All three 1956 Mercury motors are rarer than the 1955 but, they are not considered rare motors. The red and sand version was the only 1956 motor available with off-white battery wires.

Notable Traits:

Height: 5.5 inches

Red and sand version – most common version of the three available color combinations offered in 1956

“Japan” in raised letters under cowl tray towards rear

First production year offering multiple color combination Mercury’s

Off-white battery wires with red and blue insulators

“Arrow” Mercury decal

Solid driveshaft between motor and propshaft

2-Blade Prop

Offered in same brown box with black Mercury graphics same as the 1955 model

Came with instruction sheet, white plastic stand and metal battery post terminals

3 to 6 Volts

Rarity: 2.5/5
Desirability: 3.5/5
Value: 3/5

*Ratings based on 1-5 with 1 being least and 5 being most

The primary updates for this motor are the “wavy” Mercury cowl decal and the updated faceplate decal with the black oval Mercury logo. This model year is one of the more common Mercury motors available but, it is rarer than the 1955 and the more common 1956 models.

Notable Traits:

Height: 5.5 inches

“Japan” in raised letters under cowl tray towards rear

Off-white battery wires with red and blue insulators

“wavy” Mercury decal

Solid driveshaft between motor and propshaft

2-Blade Prop

Offered in brown box with updated green “wave” Mercury graphics

Came with instruction sheet, white plastic stand and metal battery post terminals

3 to 6 Volts

Rarity: 2.5/5
Desirability: 3.5/5
Value: 3/5

*Ratings based on 1-5 with 1 being least and 5 being most

The ”Cream Mercury” is so nicknamed for its cream-colored paint. The cowl decals are a white or light cream color as well with a red faceplate decal. the “Cream Mercury” is the rarest and most valuable K&O Mercury. It is believed that this model never entered mass-production because the colors were never approved by Mercury. 1957 is also the first year of the “large” 6 cylinder Mercury motors.

Notable Traits:

EXTREMELY RARE motor

Height: 6 inches

“Japan” in raised letters beneath cowl tray towards front

Only Mercury available in all cream color paint

First production year for “large” 6 cylinder Mercury’s

White battery wires with red and blue insulators

Cream colored Mercury cowl decal with red faceplate decal

Solid driveshaft between motor and propshaft

3-Blade Prop

3 to 6 Volts

Rarity: 5/5
Desirability: 5/5
Value: 5/5

*Ratings based on 1-5 with 1 being least and 5 being most

The red (sunset orange) and sand color Mark 75 motor is the first mass-produced “large” 6-cylinder Mercury. Unlike the cream-colored Merc, this version had a real-life counterpart color scheme that was offered by Mercury. This Mercury is not a rare motor but, it’s rarely seen for sale as owners tend to keep them once acquired.

Notable Traits:

Height: 6 inches

“Japan” in raised letters beneath cowl tray towards front

Not a rare motor, but not commonly seen for sale

First production year and model for “large” 6-cylinder Mercury’s

White battery wires with red and blue insulators

Solid driveshaft between motor and propshaft

3-Blade Prop

Offered in brown box with updated green “wave” Mercury, “Marathon six” and “mark 75-E” graphics

Came with instruction sheet and white plastic stand

3 to 6 Volts

Rarity: 3.5/5
Desirability: 4/5
Value: 4/5

*Ratings based on 1-5 with 1 being least and 5 being most

The green and light blue Mercury is one of two color combinations available in 1958. This version is the rarer of both color combinations offered but, both motors are very rare and highly desired. These are the only models that directly mimic the Langcraft brand designed motor. The proportions vary from the earlier K&O Mercury Mark 55 models. This motor has a shorter height and an oversized cowl. It’s believed in 1958 the K&O brand Mercury Mark 55’s were produced using the same molds/dies as the Langcraft brand. The green and light blue version comes with the K&O “fork” terminals whereas the red and sand version of this motor has the same pin-connectors often seen on Langcraft brand motors. Although these are similar to the Langcraft brand motors, but only the K&O versions had the “Mercury” branded logo.

Notable Traits:

Height: 4.75 inches

No country of origin stamping on lower unit as seen on other K&O brands

Very rare motor and highly desired

Produced by the Langcraft company

Second production year offering multiple color combinations

White battery wires with red and white insulators (Only Mercury model to be offered with the white and red insulators)

Solid driveshaft between motor and propshaft

2-Blade Prop

Offered in the “painted” full-color K&O box featuring rendering of the motor – both color combinations were offered in the same box

Came with instruction sheet - no stand included

3 to 6 Volts

Rarity: 4.5/5
Desirability: 4.5/5
Value: 4.5/5

*Ratings based on 1-5 with 1 being least and 5 being most

The red and light blue motor is one of two color combinations available in 1958. This version is the more common of both color combinations offered but, this motor is still very rare and highly desired. These are the only models that directly mimic the Langcraft brand “Mercury” motor. The proportions vary from the earlier K&O Mercury Mark 55 models. This motor has a shorter height and an oversized cowl. It is believed in 1958 the K&O brand Mercury Mark 55’s were produced using the same molds/dies as Langcraft brand. The red and light blue version comes with the Langcraft pin-connector terminals whereas the green and sand version of this motor has the K&O “fork” terminals. Only the K&O brand versions of this motor carry the “Mercury” branded logos.

Notable Traits:

Height: 4.75 inches

No country of origin stamping on lower unit as seen on other K&O brands

Very rare motor and highly desired

Produced by the Langcraft company

Second production year offering multiple color combinations

White battery wires with red and white insulators (Only Mercury model to be offered with the white and red insulators)

Made with Langcraft pin-connector terminals (Only K&O to have pin-connector terminals)

First year with “Spring-drive” drivetrain

2-Blade Prop

Offered in the “painted” full-color K&O box featuring rendering of the motor – both color combinations were offered in the same box

Came with instruction sheet - no stand included

3 to 6 Volts

Rarity: 4/5
Desirability: 4.5/5
Value: 4.5/5

*Ratings based on 1-5 with 1 being least and 5 being most

This motor shares the same design and coloring as the 1957 Mark 75. The only update for the Mark 78 was a slightly thinner “Mercury” cowl decal and a faceplate decal showing “Mark 78”. This Mercury is much rarer than the 1957 Mark 75 motor but, not as rare as the two 1958 Mark 55 motors. Like many 6-cylinder Mercury motors, these are rarely seen for sale.

Notable Traits:

Height: 6 inches

“Japan” in raised letters beneath cowl tray towards front

“Oil” is in raised letting on lower unit

Not a very rare motor, but not as common as the 1957 Mark 75

White battery wires with red and blue insulators

Solid driveshaft between motor and propshaft

3-Blade Prop

Offered in brown box with updated green “wave” Mercury, “Marathon six”and “mark 78-E” graphics

Came with instruction sheet and white plastic stand

3 to 6 Volts

Rarity: 3.5/5
Desirability: 4/5
Value: 4/5

*Ratings based on 1-5 with 1 being least and 5 being most

The Mark 78A is one of two “large” 6-cylinder Mercury’s offered by K&O for 1959. These motors were updated with a new faceplate decal, all white paint, blue Mercury cowl logo and a more pronounced “squared” cowl top. These motors also have two “hydraulic pistons” added to the transom bracket. This Mercury is one of the more common Mark 75’s available. Like many 6-cylinder Mercury motors these are rarely seen for sale and highly sought agfter.

Notable Traits:

Height: 6 inches

“Japan” in raised letters beneath cowl tray towards front

Semi-rare – very desirable motor

First year for the painted trim ring

White battery wires with red and blue insulators

Solid driveshaft between motor and propshaft

3-Blade Prop

Offered in brown box with updated green “wave” Mercury and “mark 78A” graphics

Came with instruction sheet and white plastic stand

3 to 6 Volts

Rarity: 3.5/5
Desirability: 4/5
Value: 4/5

*Ratings based on 1-5 with 1 being least and 5 being most

The Mark 78A with “Gas Tank” is one of two “large” 6-cylinder Mercury’s offered by K&O for 1959. This motor was also named and marketed as the “Drink Mixer”. The Mark 78A with “Gas Tank” was originally sold as a novelty drink mixer, not a toy. This motor would sit on the rim of your glass and mix your drink. (Probably not a good idea as these motors generally leaked oil!) The drink mixer motor shared the same design as the 1959 Mark 78A and came with a small red “gas tank” that housed the motors batteries. The battery wire was also a thick single black cable that plugged into the gas tank with a stereo-jack style connector. This was the only motor offered by K&O with this battery pack configuration. This Mercury is much rarer than the 1959 Mark 78A and is very highly desired. The battery “gas tank” is usually missing and can be very hard to find on its own. Like many 6-cylinder Mercury motors these are very rarely seen for sale and highly sought after.

Notable Traits:

Height: 6 inches

“Japan” in raised letters beneath cowl tray towards front

Rare and very desirable motor

Only motor to come with a Mercury battery pack “gas tank”

Was originally sold as a novelty “drink mixer” and not as a toy

Single thick black battery wire with stereo jack-style connector

Solid driveshaft between motor and propshaft

First year for the painted trim ring

3-Blade Prop

Both the motor and gas tank came in separate brown boxes.

The motor was offered in a brown box with updated green “wave” Mercury and “mark 78A” graphics

The “gas tank” was offered in a small brown box with green Mercury graphics

Came with instruction sheet and white plastic stand

3 to 6 Volts

Rarity: 4.5/5
Desirability: 4.5/5
Value: 4.5/5

*Ratings based on 1-5 with 1 being least and 5 being most

1959 was the first year for the small Mercury Merc 200. The Merc 200 is the smallest Mercury motor available in 1959. These were made of a much cheaper tin alloy rather than diecast metal. The 1959 and 1960 models are the same design with different color Mercury branded decals. Only the 1959 Merc 200 was available in the K&O “painted box”. The 1959 Merc 200 came with blue decals but, depending on light exposure, they can sometimes appear with a greenish hue.

Notable Traits:

Height: 4 inches

“Japan” in raised letters on transom bracket

Tin construction – cheaply made and rarely in working condition

This motor is not rare but, the “painted” box is rare

White battery wires with red and light blue insulators

“Spring-drive” drivetrain between motor and propshaft

2-Blade Prop - smaller dimensions than larger motors

Offered in “painted” box with motor graphics

Came with instruction sheet - no stand included

3 to 6 Volts

Rarity: motor alone: 1/5 - motor with box: 3.5/5
Desirability: motor alone: 1.5/5 - motor with box: 4/5
Value: motor alone: 1/5 - motor with box: 3.5/5

*Ratings based on 1-5 with 1 being least and 5 being most

This motor shared a similar design to the 1959 Mark 78A with updated red Mercury decals and a satin-black painted cowl wrap. This Mercury is very rare but, not as rare as the 1961 Merc 800 and 1962 Merc 1000. Highly desirable motor and very hard to find.

Notable Traits:

Height: 6 inches

“Japan” in raised letters beneath cowl tray towards front

Rare and very desirable motor

First year for the painted cowl wrap

White battery wires with red and blue insulators

Solid driveshaft between motor and propshaft

3-Blade Prop

Offered in brown box with black “Merc 800” Mercury graphics

Came with instruction sheet and white plastic stand

3 to 6 Volts

Rarity: 4/5
Desirability: 5/5
Value: 4.5/5

*Ratings based on 1-5 with 1 being least and 5 being most

The second year for the small Mercury Merc 200. This motor is the smallest Mercury motors available in 1960 and made of a cheap tin alloy metal. The 1960 model is the same motor as the 1959 but, with a red Mercury branded decal instead of blue. The 1960 Merc 200 was only available in plain brown box with green Mercury graphics. This motor is slightly rarer than the 1959 Merc 200 but, not a rare motor.

Notable Traits:

Height: 4 inches

“Japan” in raised letters on transom bracket

Tin construction – cheaply made and rarely in working condition

Available in a brown box with green Mercury graphics - no instruction sheet or stand included

White battery wires with red and light blue insulators

“Spring-drive” drivetrain between motor and propshaft

2-Blade Prop - smaller dimensions than larger motors

3 to 6 Volts

Rarity: 1.5/5
Desirability: 1.5/5
Value: 1.5/5

*Ratings based on 1-5 with 1 being least and 5 being most

This motor had multiple updates to its design for 1961. The faceplate now came with an elongated chrome trim piece that runs along the top of the cowl. The lower unit is now thicker and no longer has the “hourglass” shape from previous years. The prop was also updated to a thru-hub exhaust design. The Mercury branded cowl decals are now silver, and the trim ring is chrome instead of painted. These decals often look “yellow” but, the yellow color is from the clear decal material aging. 1961 was the first year for “spring-drives” in the large K&O Mercury motors. This Mercury is VERY rare but, not as rare as the 1962 Merc 1000.

Notable Traits:

Height: 6 inches

“Japan” in raised letters beneath cowl tray towards front

Very rare and very desirable motor

New design for 1961 - notably faceplate, decals, lower unit, prop and drivetrain

White battery wires with red and green insulators

First V-6 Mercury to come with “Spring-drive” drivetrain between motor and propshaft

2-Blade Thru-hub exhaust prop

Offered in brown box with black “Merc 800” Mercury graphics

Came with instruction sheet and white plastic stand

3 to 6 Volts

Rarity: 5/5
Desirability: 5/5
Value: 5/5

*Ratings based on 1-5 with 1 being least and 5 being most

The third and final year for the small metal Mercury motor. This motor is the smallest Mercury motor available in 1961 and made of a cheap tin alloy. The 1961 model has an updated look from the 1959-60 Merc 200’s. The 1961 Merc 60 has updated lined cowl wrap decal and Mercury branding. This motor was available in plain brown box with black Mercury graphics. This motor is semi-rare but, doesn’t have the desirability of the Mark 55’s or V-6 Mercury motors. This motor is often found with damaged decals due to their large size and the side cowl screws placement.

Notable Traits:

Height: 4 inches

“Japan” in raised letters on transom bracket

Tin construction – cheaply made and rarely in working condition

Last year for the small tin Merc motors

Updated cowl design

White battery wires with red and light blue insulators

Available in brown box with black Mercury graphics - no instruction sheet or stand included

“Spring-drive” drivetrain between motor and propshaft

2-Blade Prop - smaller dimensions than larger motors

3 to 6 Volts

Rarity: 2.5/5
Desirability: 2/5
Value: 2/5

*Ratings based on 1-5 with 1 being least and 5 being most

The Merc 1000 is One of the rarest and most valuable motors offered by K&O. This motor maintained a similar body and prop design as the 1961 Merc 800 but, featured multiple visual updates. The motor now appears in all satin-black paint with an updated cowl wrap that incorporates the Mercury logo. The transom screws and cups were painted the same black color as the rest of the motor . This was the only year for unpainted transom “pistons”. The battery wires were also updated to an all-black insulation rather than the white seen in previous years. The quality of the Mercury decals for this motor was very poor and often have poor adhesion or severe chipping. HANDLE WITH CARE! These Mercury decals are easily chipped or flake off with handling. This motor is very rare and extremely desirable.

Notable Traits:

Height: 6 inches

“Japan” in raised letters beneath cowl tray towards front

Very rare and extremely desirable motor

All satin-black paint

Black battery wires with red and green insulators

Nicknamed “Tower of power” – first motor to have 100HP

2-Blade Thru-hub exhaust prop

Offered in brown box with black “Merc 1000” Mercury graphics

Came with instruction sheet and white plastic stand

3 to 6 Volts

Rarity: 5/5
Desirability: 5/5
Value: 5/5

*Ratings based on 1-5 with 1 being least and 5 being most