What rpm range do you normal cruise ?

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chrismele

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I'm interested in seeing what other find is the best rpm (range) to cruise at. Thanks. Chris.
 
I'd opine that the sweet spot for 2-strokes is typically ~4,000 to 4,200 and about 4,500 for 4-strokes, from my experience w/ said V-6 motors on boats running fuel computers.

'Sweet spot' would be best fuel economy/range.
 
I run 4200 rpm 24-30 mph depending on seas at 2.4 - 3.0 mpg.
 
DaleH":3foirjta said:
I'd opine that the sweet spot for 2-strokes is typically ~4,000 to 4,200 and about 4,500 for 4-strokes, from my experience w/ said V-6 motors on boats running fuel computers.

'Sweet spot' would be best fuel economy/range.

I too agree, I cruise @ 4,100 28/29mph with 1/2 tank or less fuel z250 Hpdi
 
chrismele":2ozsk2n7 said:
I'm interested in seeing what other find is the best rpm (range) to cruise at. Thanks. Chris.

The question/answers are meaningless without the context of hull/engine. My 2015 1801 with a 115 Yamaha loves 4000-4200, 30-32 MPH, ~ 5 GPH. She will run almost 40 MPH, but fuel burn goes up to 10 GPH plus.
 
Wow, I wish I had the speed many of you are reporting at the relatively low RPM ranges. With a moderate load and calm seas, I cruise at about 25 mph and 4600 rpm and 1.9 to 2.2 mpg (statute). If I'm in a hurry I'll crank it up to 4800 rpm and move at around 27 mph and about 2.0 mpg (my mpg paradoxically gets better the faster I go - my MPG is the same at WOT as it is at cruise - around 2.0 to 2.2).

According to my calculations, at regular "cruise" speed (25 mph) the prop is slipping about 15% to 20%

2330EC with Honda 225 on a Stainless Marine bracket, 13p Honda (Solas) stainless prop (which I'm hopefully replacing soon).
 
'd opine that the sweet spot for 2-strokes is typically ~4,000 to 4,200 and about 4,500 for 4-strokes, from my experience w/ said V-6 motors on boats running fuel computers.

Exactly what I see with my Yami HPDI 200 hung on my 23 SE CC, hard top, spray booth on - 4000-4100 w/ an average load of 3-4 adults, 1/2 tank of fuel, fishing gear, other typical gear almost spot on 30mph conditions permitting. Rev 4 prop, BTW.
 
Guys,

For those of you who posted numbers, can you also edit your original post to include what pitch prop you are running? This would be interesting to calculate everyone's average "slip" value for their optimal cruise.

Just with the sample data provided so far, I put together this little chart that shows relative "performance" if one considers more speed for a given RPM to be a "good" thing. (this is assuming no one is having problems with holeshot or hitting WOT).

One would expect the larger motor (i.e. 300) to be "best" since it has the extra grunt to swing a larger pitch prop and push the boat faster. The 'anomaly' is the 2520 w/ a 300 that is turning 4400 and only doing 25 mph. (Warthog). Granted this is a VERY small data set, so no definitive conclusions can be drawn, but its interesting in terms of ranking. Also "ideal cruise" is a very subjective term. Some people might think ideal cruise is 50 mph and 5,000 rpm. :D

2015-12-07_18-13-19.png
 
Brent, nice graph. Here is a copy of a previous post I did showing my data points. This was right after I raised my motor and installed the Permatrim but before I added the 12 X 18 tabs. I always have my info on the GPH, with I had toggled to both for the MPG. I've not done this since the tabs. Maybe next season?
 

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My ideal cruise is about 4300 rpm traveling about 29-31mph depending on weather. I've got the F300 on a 2520 MV.
 
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