OBR Parts & Marine

Break-In Procedures

Lower Unit and Sterndrive

  1. Gearcase assemblies are shipped without oil.
  2. Fill unit with manufacturer's required gear oil to recommended level.
  3. Adjust RPM at idle to manufacturer's specifications.
  4. Proper shift adjustment is essential.
  5. JUMPING OUT OF GEAR:If the unit will not stay in gear, the clutch dog has probably been rounded off. Rounded clutch dogs are caused by, but not limited to, improper shift cable adjustment, inadequate shift travel, idle RPM too high, and / or shifting too slow Rounded clutch dogs are NOT covered by warranty.
  6. Avoid full throttle starts.
  7. DO NOT operate at constant speed for extended periods.
  8. Shift into forward gear a minimum of 10 times during break-in, with moderate engine speed after each shift.
  9. DO NOT exceed 75% of full throttle during the first five hours of operation.
  10. During the next 5 hours, full throttle should not be maintained for long periods.


When purchasing either an upper or lower assembly separately, the opposite piece must be disassembled and cleaned by the service center in order to validate the warranty. This provision is due to the cross contamination of the oil.


  • Do not perform break-in on water hose.
  • Double your oil with a major manufacturer TCW-3 oil. (Excludes direct injected engines.)
  • Use a mid-grade octane major manufacturer fuel without alcohol.
  • Liquid cooled engines should be slowly brought up to normal operating temperature to avoid cold seizure.
  • For the first hour, operate the engine at a varied speed of 700-1500 RPM to break-in new pistons and rings.
  • During the next 6 hours, operate the engine in gear at no more than 3,000 RPM. Accelerate using only enough throttle to bring the boat up on plane quickly and bring the throttle back to maintain a minimum plane speed.
  • Vary your engine speed by accelerating to 3/4 throttle for 1 to 2 minutes, then back to minimum plane speed.
  • During the final 3 hours you may operate the boat at wide-open throttle for periods of less than 2 minutes.
  • It is very Important to avoid operating at a constant speed of 3,000 to 4,000 RPM or continuous full throttle for the first 10 hours. This is the economy range in which the timing is at full advance and carburetor or fuel injec- tion is running lean. This could lead to overheating and piston detonation.
  • Cylinder heads should be re-torqued after the 10 hour break-in period.


This powerhead is replacing one that has failed prematurely. Powerhead failure is usually due to excessive combustion chamber temperature. You must find the cause of this failure or the same problem will occur again. Our experience is that the piston is the part that fails first, usually caused by detonation. The following tips may help you avoid repeat failure:

  • Have all injectors cleaned and flow tested. Replace injectors that are out of specification.
  • Check the entire fuel system including fuel pump, line filters, carburetors, etc.
  • Increase main metering jets by.002.
  • Retard ignition timing by 2 degrees.
  • Replace or check all switch boxes and ignition modules.
  • On Mercury motors, remove idle stabilizer and advance module.
  • Verify high and low fuel pressures are within specification.


  • Install.002 larger main jets in carburetors.
  • Retard maximum timing 2 degrees. Set Max timing with engine running over 4500 RPM under load.
  • Do not set max timing static.
  • Replace water pump and gaskets at time of powerhead replacement and every year. Use newest style gaskets.
  • On 3-cylinder engines, replace the water pump with the late model high pressure style, check all OMC service bulletins and jet carburetors accordingly.
  • We recommend installing a water pressure gauge to monitor water flow in the engine.
  • Use mid-grade octane major manufacturer fuel without alcohol.
  • We recommend removing the oil injection system or updating to the latest VRO pump.
  • Clean and refill oil tank with TCW-3 oil.
  • Verify oil consumption by marking oil tank during double oil break-in period.
  • Double your oil with a major manufacturer TCW-3 oil for approximately 30 gallons of fuel. If running oil injection, add 1 pint of oil to 6 gallons of gas. If no oil injection add 1 quart of oil to 6 gallons of gas. Does NOT apply to direct injected motors.
  • Re-torque cylinder heads after one hour running time, after engine has cooled.
  • Rebuild carburetors and / or fuel pump.
  • Check overheat and oil alarm horn for proper function.


  • Install.002 larger main jets in carburetors.
  • Rebuild or replace carburetors and fuel pump.
  • Retard maximum timing 2 degrees.
  • Remove advance module and idle stabilizer if on motor.
  • Replace water pump and all gaskets at time of pow- erhead replacement and every year. Use newest style gaskets.
  • Use a mid-grade octane major manufacturer fuel without alcohol.
  • We recommend removing the oil injection system. If oil injection is used, replace 2-PSI oil valve and check oil pump bushing and seal.
  • Clean and refill oil tank with TCW-3 oil. Verify oil consumption by marking oil tank.
  • Make sure trigger wires on flywheel are free moving for proper advance.
  • Re-torque 2.0/2.4/2.5 cylinder heads to 40ft. lbs. after 1 hour running time, after engine has cooled.
  • Check overheat alarm system and horn. Beware of problems with detonation sensor and module.
  • On 2.5 EFI engines, there are as many as seven fuel filters.
  • Remove the cone-shaped filter in the line below the electric pump. Verify fuel pressure is to specification
  • Check all latest factory specifications and service bulletins.

With nearly 10,000 authorized dealers nationwide, OBR Parts and Marine is the largest supplier of outboard and sterndrive replacement components in the nation.

No one in the industry can compete with our inventory or service. As an OBR authorized dealer, you will benefit from years of technical expertise, personal customer service, a generous exchange policy, and the most competitive pricing structure in the industry. In short, your membership in our DealerNet enables you to better serve the most important people in your business..... your clients!


Simply email or fax your business license and business card or letterhead to accounts@obrparts.com or 251-645-2084. Be sure to include you contact name and phone number so we can reach you after the setup is complete.