Johnson Service Promotion Bulletins / SPB #399
Johnson Motors Service Promotion letterheadSPB-#399

December, 1967

SUBJECT: OMC ACCESSORIES ENGINE CLEANER

OMC ACCESSORIES ENGINE CLEANER is an internal engine cleaner designed to clean piston tops, ring grooves, and cylinder walls of engines that are moderately coated with petroleum gum and varnish without having to dismantle the powerhead.

Original OMC Accessories Engine Cleaner gallon and pint cans

The necessity for having a good internal engine cleaner becomes evident when remembering that under certain conditions it is possible for pistons and cylinder walls to accumulate a thin coating of petroleum gum or varnish. These gum and varnish substances are rather sticky, which, over a period of time and for no apparent reason, result in excessive piston drag and ring to piston seizure. The overall result is sluggish engine performance as evidenced by gradual R.P.M. loss. In extreme cases, complete piston to bore seizure results, particularly after periods of storage.

Therefore, when looking for a satisfactory and time saving method to remove much of this gum and varnish without having to tear down the engine, OMC ACCESSORIES ENGINE CLEANER is recommended. It should be noted, however, that this is a CLEANER, not a preventative, and must be used in strict accordance with the following procedure:

  1. Run engine to normal operating temperature.
  2. Remove spark plugs and set pistons so intake and exhaust ports are closed.
  3. Tilt engine to horizontal position with spark plug holes up.
  4. Cover top of pistons with OMC ACCESSORIES ENGINE CLEANER.
  5. Let stand in horizontal position for 30 minutes or longer (overnight in extreme cases).
PAGE 2SERVICE BULLETIN  SPB-#399JOHNSON MOTORS, DIVISION OF OUTBOARD MARINE CORPORATION, WAUKEGAN, ILLINOIS  60085
  1. Turn engine over so spark plug openings face downward. Pull starter handle several times so as to force fluid out through spark plug openings.
  2. Put engine in test tank, replace plugs (cleaned & regapped) and run engine to normal operating temperature.

    NOTE: Starting engine may be more difficult than normal because piston and cylinder surfaces are wet with cleaner; particularly if the spark plug electrodes are fouled or excessively coated with cleaner, carbon and/or oil. To ease starting effort, clean and regap spark plugs before starting engine.

  3. Slowly run 2/3 of a pint can of ENGINE CLEANER through carburetor throat at fast idle.
  4. Increase speed and pour balance of cleaner in fast enough to stall engine.
  5. Let stand for another 30 minutes or longer.
  6. Start engine and run at advanced throttle for five minutes.

    NOTE: For engines which are to be operated on a boat following the cleaning operation, Step 11 completes the cleaning process. However, if engines are to be placed in storage for ANY length of time, complete Step 12.

  7. Fog engine thoroughly with OMC ACCESSORIES RUST PREVENTATIVE.

    CAUTION - NOTE: Step 12 is extremely important to adequately protect engines in storage and MUST NOT BE OMITTED after cleaning.

OMC ACCESSORIES ENGINE CLEANER is available in one pint and one gallon cans. Order by part number as follows:

171699 Pint Can (24 Cans per Case)Suggested List Price Per Can$1.80
171702 Gal. Can (4 Cans per Case)Suggested List Price Per Can$12.00

The 40% accessory discount applies to either purchase. ORDER ONLY FROM YOUR PARTS DISTRIBUTOR.

JOHNSON MOTORS

J. R. Penland
Service Promotion Manager

JRP/rkm