Break-In Operation; Test Run - TOHATSU MFS 25D Service Manual

Service Information

5. Break-in Operation

B r e a k - i n o p e r a t i o n i s n e e d e d f o r t h e p u r p o s e o f
smoothening the sliding surfaces between components
such as pistons and cylinder, piston rings, piston pins,
crankshaft, connecting rods, and intake and exhaust
valves.
• In order to apply an appropriate load on each
part during the break-in operation, run the test
with the propeller mounted.
• During the break-in operation, change the
revolution speed while keeping it equal to or
below the specified revolution speed.
Break-in Operation...10 hours
Time 0
Break-in
Operation Method
It is best to fluctuate the engine RPM (Target RPM or less) every 15-30 mins at each stage during the break in
procedure to allow for complete break in of outboard engine.
Running the outboard at for prolonged periods such as idling or one specific RPM is detrimental to the outboard and
could affect engine reliability and performance.

6. Test Run

1. Start the engine and check if the gear can be shifted
smoothly.
2. After completing the warm-up operation, check the idle
revolution speed.
Idle Revolution Speed:
850 min
RPM -1
Tachometer:
P/N. 3AC-99010-0
3. Shift the gear to the Forward (F) position and run at the
dead slow speed. (About 10 minutes)
Dead Slow Revolution Speed:
850 min
-1
RPM
1-16
10 minutes
Throttle Opening
Trolling
or Hereinafter,
approximately
idling
3,000 min
Running at the
slowest possible
speed
(rpm)
(rpm)
2 hours
Throttle Opening
1/2 3/4
Hereinafter,
approximately
(rpm) 4,000 min (rpm)
-1 -1
Can be operated
fully open for about
1 minute every 10
minutes
3 hours 10 hours
Throttle Opening
3/4
Regular Operation
Approximately
4,000 min (rpm)
-1
Can be operated
fully open for about
2 minute every 10
minutes
4st 25/30 2022