Cruising RPM Yanmar 36

[Philippe Rouleau]

I just bought a new Hunter 380 with a Yanmar 36hp. Can someone tell me what RPM would be good for a long cruise ? The dealer told me 3500 rpm which I find high.

 

[Chuck Wolfe]

Yanmar RPM's

I have a different Yanmar (1992) and my max according to Yanmar is 3450 RPM's. By 1994 the Yanmar's had upped the HP a bit and the max RPM's was 3600 full throttle under load. Call Yanmar at 1-800-622-5364 and give them your model number. They'll tell you although it should be in the manual.chuckwolfe@mail.com

 

[Bob Knott]

380 RPM

Our 99 380 max's out at 3600 RPM. The manual says to run it at near full RPM only ocasionally to clean out built up carbon. Most times 2800 RPM gives decent speed (The boat is not fast with this size motor) and fuel economy. 3200 RPM is ocassionally necessary when heading into slop. At 2800 RPM with a clean bottom we'll do 5.8Knots at 3200 we can average 6.2K The 4/10k pickup is nice but the motor burns 20% more fuel to pick up the 4/10 so it's really not worth it.Hope this helpsBob KnottH380

 

[Patrick Ewing]

Engine Speed

I have a 91 37.5 with a 3HM35F engine. I cruise at 3000 rpm or so. Max is about 3400 and she starts to run hotter at anything over 3200. I just put on a 3 blade 18 inch Max-Prop and that gave us about 0.8 to 1.0 knots more speed. Now we cruise at 7.7 knots at 3000. Had a 2 blade Max-Prop which vibrated badly and was even hitting the hull at some speeds. The new prop is much better - no vibration and more speed and power into the weather. I haven't figured the fuel consumption yet but it cost me almost $2.00 per gallon yesterday.

 

[Paul Bednarzyk]

Cruising RPM

Philippe, On my 380 we cruise at around 2800 rpm. With our 3 bladed MaxProp we see roughly 6.2-6.5 kts. At WOT we see 3500rpm and can push it to 7.0-7.3 kts, but the wear and increased fuel consumption don't make it worthwhile. I find that at 2800 rpm I burn about 3/4 gallon/hour. If I drop to 2200-2300 rpm, my fuel burn goes down to about 1/2 gallon/hr.Paul BednarzykS/V Knot Again