The omc zephyr saildrive

The Sail Drive (also known as the OMC Zephyr) was built from 1977 thru 1984. It utilizes a 32 cubic inch powerhead (which commonly powers the 20/25/30 hp outboards).

The sail drive is a rather unique animal. The powerhead is "inboard" and the hull has a hole cut into it where the mid-section and gearcase end up sticking thru the bottom of the hull. The unit does not pivot to provide steering, therefore steering is handled by the boat's rudder. It does use the same powerhead as the JohnnyRude 20-30 hp outboards, but it's hp is "de-rated" - the larger displacement block provides better thrust for moving large sail boats.

According to one internet source, the following model numbers of sail drives were built:

  1. 1977   -  15S10S and 15S10G

  2. 1978   -  15S11C

  3. 1980 through 1982 - 15S13A

  4. 1983   -  15S14M

  5. 1984   -  15S14R

Parts list for the Zephyr Saildrive can be found on the documents page.

Spark Plug Cross Reference:

  1. Champion - L-81Y (this is listed in OMC material)

  2. NGK Brand - BP7HS

  3. Bosch - W5B

  4. AC Delco - 41FS

  5. Motorcraft - AE12

  6. Another Champion number - QL8YC

Note:  The cross-referenced model numbers were obtained from the internet, and have not been verified.  Your mileage may vary.

The documents section of this web site has a ton of technical information about the Sail Drive.

RACOR gas/water filter information here

TIPS (most taken off the Saildrive Yahoo Groups list):

Changing the Saildrive Lower Unit Oil:

 There are three "screws" on the starboard side of the lower unit. The one COMPLETELY on the bottom and the one COMPLETELY at the top are the two openings for servicing the lower unit with gear grease.

Place a container near the unit on some kind of stand because the grease/oil is easily blown around by any amount of wind. Then remove the common (slotted) screw/drain at the bottom. Then remove the screw/plug at the top of the unit and this will allow air pressure to equalize and the grease will begin to flow. It holds about a quart and takes a while to drain completely. Allow it to drain for at least 30 minutes since it will be cool and thick. 

DO NOT REMOVE THE PHILLIPS SCREW ON THE LOWER UNIT! This goes into the transmission and if you pull it you will have to pull the engine to replace it. Take care!

Go to a marine supply store and get an inexpensive hand pump which fits a 90 weight quart bottle of lower end grease. A quart will do it. Attach the pump to the lower drain and pump with the upper plug out till grease flows from the top of the unit. When this happens then the unit is full. Replace the top plug, this creates a partial air lock so when you remove the servicing pump not too much grease will be lost.

Quickly install the lower drain plug. Make sure both plugs are nice and tight and that the "O" rings are in place. The grease you need is the 90 weight outboard lower end grease. Don't buy the stuff for electric shift gear boxes as it is too light for our lower unit. The pump and grease are available at West Marine or any full service marine supply store.

To Repeat: Take care not to touch the phillips head

screw on the side of the lower unit housing.

You should be able to obtain the Zinc from Bombardier.


What you should know

Zephyr photos

zephyr saildrive links


The OMC Zephyr Saildrive