A site for antique outboards, mopeds, and select automobiles

Home About Me Antique Outboards Mopeds Cars Contact Me Stories Outboards in Media Odds and Ends

Neptun - M (Soviet built)


Rival concern to the Whirlwind/Vihor in our collection is the Soviet/Russian built Hentyh or Neptun. (not a spelling error!) Like the Whirlwind it is a two cylinder, 2-stroke, water cooled outboard of 20 horsepower. Research indicates it was made by the Moscow Machine-Building Enterprise in a factory with the awesome name: Red October!

A look on various Russian boating web sites (with the help of Google Translate) indicates that Neptun outboards can be traced back to about 1963, though it appears they didn't offer their first motor until 1965 with some sources saying 1967. Some of the material indicates the designers drew heavily on the Swedish Archimedes and Penta models of that time. The initial model started at 18hp, the motor seen here is the improved version (hence the "-M" after the name) of 20hp. The year of the changeover is unclear, probably 1969 or thereabouts. Starting in 1971 an even more improved model was offered at 23hp and, with some major updates, was in production for many years being one of the most popular outboards in Russia.

I received several eMails and calls from friends that this "Soviet Outboard" had popped up on the western Mass craigslist and just had to take a look. It came from the original owner who purchased it new in 1972 at a sporting goods store in Moscow! Since this is the 20hp variant, it is unclear if it was a leftover or if the 20 and 23hp models were offered simultaneously. In 1976 the owner emigrated to the USA and brought the motor with him. It was used on several vacations to Maine but laid-up in 1979 and not run since.

Collecting old outboard brings you into contact with some very interesting people. It was a genuine pleasure to meet the 80-year-old gentleman who sold the motor to me, hear about his life and the history of the motor. He is someone we can all look up to and someone who doesn't take the freedoms we have here in the USA for granted. He came to the USA from the Soviet Union with $9 in his pocket (and an outboard!) and subsequently made a good life for himself and his family. A true American success story!

Other than being a bit dirty, the motor appears to be in great shape and not have a lot of hours on it. More as soon as I get into it. On the face of it, this motor has a lot better casting work, engineering, styling and paint than the Whirlwind/Vihor that I have. These two motors were made within a couple of years of each other so they can be considered contemporaries. The Neptun delivers more hp per cc, has a higher max RPM (by 500 revolutions) and is lighter by 12lbs. My opinion seems consistent with many comments glimpsed on the Russian boating web sites I visited. People seem to universally hate the Whirlwind and have a real fondness for the Neptun!

Year & Model: 1972 Neptun-M (??????-M)
Horsepower: 20@5,000 rpm
2-Alternate firing - loop charged
Bore: 61,75
346 cc
Ignition: Magneto
Point Gap:0.3-0.35mm
Lighting: 12 volts and 40 watts (For running lights)

Cooling: Water by rubber impeller

Condition: Unrestored
Retail price when new:
Weight: 43 kg (94 lbs.)
Oil/Gas Mix: 20:1 with TCW-3
Spark Plug: CH-12 Standard 2043-54 (Translated from the manual, I am not sure what this means!)

Seems to be a lot nicer motor than the Whirlwind! More as soon as I get it into it and get it running.

Here are a few photos as I go through the motor - click on them for a larger image:
Port-side of engine
Starboard side of engine
Carb close-up - slider/meter valve on top comes off with two clips making it super easy to take the carb off and service. Way better than the 1972 OMC 6hp carb that had the nut hidden in back of the starter....
Magneto - two are charge coils and two provide 12v and 40w for running lights, your electric razor, etc... The condensers tested okay but were higher microfarads than I typically see on USA made outboards: 35 and 40 respectively.
The points incorporate a crazy number of individual parts. Mine required a through disassembly, cleaning and de-greasing to allow the electrons to flow. Since I needed to take a photo to ensure I re-assembled all the parts in the correct sequence, I thought others would appreciate the photos above - just in case...
Carburetor off the motor
In case there is any doubt, this translates to "Manufactured in the USSR"
Making up for the stupid number of parts in the points, the carb is a wonderwerk of simplicity and super easy to service!

Further Reading

Here's a web site I found in Russia that has an on-line repair manual for both the Whirlwind and Neptun. Google Translate delivers a fairly acceptable translation - with a few interesting hiccups: http://motorka.org/book/vihr_neptun/

As with the Whirlwind/Vihor, be sure to check out the fantastic 2010 documentary by Werner Herzog called HAPPY PEOPLE: A Year in the Taiga and see several different Russian motors at work. Quite a few Whirlwinds, several Neptuns and what I think is a Bemepok are used by trappers under some pretty tough conditions. As of this writing in December 2014, it is available on Netflix.


Atco Boatimpeller | Bendix | British Seagull | Caille | Champion | Chris Craft | Dragon Fly | Elgin | Elto | Evinrude | Flambeau | Johnson | Lauson | Lockwood Ash | Mac10 Wankel | Martin | Mercury | Misc.Motors | Oliver | Outboard Jet 200 | Pluvier | Scott-Atwater | Tohatsu | Tomos | Volvo | West Bend | Whirlwind(Soviet) | Wizard| Yamaha | Zundapp

Home | About Me | Outboards | Mopeds | Cars | Contact Me | Stories | Outboards in the Media | Odds & Ends

The information on this website is intended for personal use only. The copying and distribution
of this information for any other purpose is strictly forbidden without prior written consent.

Copyright 2005-2016 OddJob Motors All rights reserved