Yanmar 4JH57 Break In

[SteveInMD]

I'm trying to do right by my new Yanmar 4JH57 and properly break it in. I have read the break in procedure... During the first 10 hours run the engine at 60 - 70% of load most of the time. Do not idle for more than 30 minutes and do not run at wide open throttle for more than one minute at a time.

While reading the manual I notice you can set the LCD to show "ENG Ld" which is engine load percentage.

The problem is, when I try to get to 60 - 70% of load I'm motoring along at around 9 knots and I'm getting near the max rated RPMs. I backed off and did not run that way for more than a minute. 45 - 50% of load still seems fast to me, but more reasonable.

My question is... can I trust the ENG Ld reading on the LCD? Is it accurately showing me engine load and I should run it up to 60 - 70%? If not, how am I supposed to tell what 60 - 70% is?

[Lepke]

Depending on the boat and prop, the load/rpm position will change. Bigger prop and the 70% load would happen at a lower rpm. I would run at 1/2 to 3/4 throttle during breakin.