Until our mechanics chime in:
Yanmar Break-In Procedure
Prolonged idling of diesel
engines is not good for them.
For the first 30 minutes, maintain idle to about 1500 RPM
, until the engine
temperature has stabilized, then advance to Maximum Loaded RPM
, in 200 RPM increments, over about 15 -20 minutes.
If the engine
can't reach its correct maximum RPM then slow down, return to the dock
, and have it fixed or explained*.
For the next 5 hours running don't operate the engine at more than 85% RPM (nor less than 2000 RPM) and every 20 minutes change the RPM up or down by 200 RPM. When the 5 hours are up, you’re good to go cruising.
* I’ve never been able to take a sailboat’s diesel auxiliary to Max Rated RPM.