Lucia 40: Lucia 40 with Yanmar 3YM30AE - Cruising RPMs

[SailBlue]

The Lucia 40 manual states that when equipped with a Yanmar 3YM30AE the cruising RPM should be 2,000. According to Yanmar, this engine should be ran 70% of the time at max speed- 400 RPM, which would be 2,800 RPM (Max RPM for this engine is 3,200), recommending also 4-5 mins at WOT every 30 minutes.

Any idea why the Lucia 40 manual lists such a low RPM for cruising ?

[Alistair242]

I have the same engines. I normally run them(one or both) around 2000-2200rpm. Every now and then you need to run them hard to blow out the cobwebs.
2000 RPM gives you good fuel economy and charging capacity.

[FlyingScot]

Depends if running one engine or two. Two, calmer seas, 2200-2300 RPM range and if one more like 2600-2800 RPM or so. Definitely don't baby them

[Sam Woodbridge]

Originally Posted by SailBlue

The Lucia 40 manual states that when equipped with a Yanmar 3YM30AE the cruising RPM should be 2,000. According to Yanmar, this engine should be ran 70% of the time at max speed- 400 RPM, which would be 2,800 RPM (Max RPM for this engine is 3,200), recommending also 4-5 mins at WOT every 30 minutes.

Any idea why the Lucia 40 manual lists such a low RPM for cruising ?

I have the same engine in my boat and this subject has come up before on the forums.

Never did get a confirmation on what’s right and what’s wrong. Everyone gave opinions on what they do with their own 3YM30AE.

For what it’s worth I interpret the manual the same way the OP does.

But it would be nice to hear from a mechanic that works on these motors.

[Phyrcooler]

Follow the engine operations manual! The motor doesn’t know if it’s installed in a FP or a Beneteau. There is nothing special about the hull that restricts “normal” engine operations. I have the same motor and usually run 2400 - 2800 depending on my needs/desires. (Sorry… I’m not a mechanic. If you’re still concerned, go join Boatdiesel.com. Lots of support and advice from some respected mechanics. Even then, you’re only getting the advice of someone on the internet. Even me! Which is why I say default to what the engine manufacturer tells you.)

[Sailorichiban]

After running a 3GM Yanmar for more than 15 years I can state it liked full throttle operation best. If propped correctly it achieved full rpm and was happy with 12/16 hr. Runs. Lesser power levels would reduce fuel consumption but also reduce speed. Definitely would not run at less than 70% for prolonged periods.