Engine R.P.M.

[Gary Leinberger]

I have a 1986 Hunter 34' with a Yanmar GM30 engine.I would like to know what R.P.M. is the maximum I should run it at for longer amounts of time

 

[J. Tesoriero]

Get advice from Yanmar

You should check in your engine owners manual or contact Yanmar or one of its dealers directly. I don't have all of the links but you can start with www.yanmar@marinedieseldirect.com.In general, most engine have a maximum (red line) RPM somewhere between 3,000 - 3,400 RPM. They also have a continuous rating at about 85% of the maxiumum. Most operators cruise at the lower (85%) number and stay away from the max. rotations for any extended period of time.

 

[John Horton]

I run mine at about 2200

I have the exact same boat and engine as you and run mine at about 2200 RPM. It probably wouldn't hurt to exceed that, but I on the conservative side and also like to keep the engine noise low.

 

[Steve Dion]

Too low is almost worse than too high.

Your 3GM max rating is 3600. You should run the engine in the 2500-3000 rpm range. If you run your engine at lower RPM's you will coke up the mixing elbow sooner and glaze your cylinder walls. If you run it higher they tend to belch black smoke and run hot.Check out YanmarHelp.com