76hp RPM level

[RumLine II]

I've got a 2001 76hp Turbo Yanmar. I would like to know what rpm others run this eng. at. I'm traveling the intercostal for 6 to 8 hrs per day. I've heard all differentt rpm levels from 2000 to 3200. I've never had a Yanmar before and I'm just not sure.
Thanks in advance
rumline

 

[Steve Dion]

http://www.yanmarhelp.com/operate.htm

Find your engine and determine what is right for you.

Be sure to cool your engine down when shutting down for the day. Let idle for 5-10 min. then rev engine to about 2000 rpm and pull fuel shutoff.

 

[RumLine II]

I found my # 4JH3 TE and I didn't see it listed on the chart. Is there another site I can check?
Thanks
rumline

 

[Steve Dion]

It appears that your engines max rated RPM is 3800. The normal operating range is about 80-85% of max rated. This would indicate that you would run her from about 3000-3200 rpm.

These number are based on having a prop that is matched to your engine. If everything is correct you should be able to rev your engine to 3800 rpm's when your tranmission is in gear. You also need to have a clean bottom and prop for these number to be achieved.

While the recommended RPM's may be 3000-3200 you will need to determine the "sweet spot" for your setup. I think you will see that you will consume about 1 gal./hr when running at the 2800-3000 range. You probably do not want to operate the engine under 2600-2700 for extended periods of time.

You may be able to get better fuel economy at the expense of engine glazing (see Yanmar Help for an explaination).

 

[Guest]

4JH

Our boat came equipped with a 1991 57HP 4JH2-TE driving a fixed three blade prop. We've cruised her several thousand miles all over PNW waters, a few of which have been under power. Our 4JH2 engine has a maximum of 4350 RPM, which I have tested while in neutral. This propulsion arrangement pushes our 30,000 pound boat to seven knots at 2,000 RPM and can do it all day long if needed. That is the RPM I use while cruising. I can increase the RPM to achieve a higher boat speed, but the seven knots seems to work the best for us and it also keeps the engine operating temperature at the level recommended by the manufacturer.

What kind of prop do you have on your boat and how does it work? If you have a two blade prop it may require the engine to run at a higher RPM in order to achieve the boat cruising speed you need.

Terry Cox

 

[Terry411]

Don't rev turbo engines right before you turn them off very bad for turbo's bearings let engine idle a few to cool turbo off.