RPM question

[tommybe1]

I have a df50 on a small boat used mostly for trolling. Operating range is 5900-6500 rpm. At wot I get 6000 rpm. I read somewhere that it is better for the motor to be nearer the 6500 then the 5900. Is this a true statement? Being married I don't want to buy a new prop if not needed. I'm retired and the wife still works. "I earn and you spend" I say "but that's the way it should be dear" Woman has no sense of humor. Thanks in advance for any light you can shed.

[Moonlighter]

Where did you get that rev range from?

I have not seen such a range mentioned in the official specs myself?

I saw a max rpm of 6000 for the DF50 and 5300-6300 for the Df50A.

So at 6000 you are right “on the money”. No change needed.

[tommybe1]

Got it from the service manual (1999 - 2011. df40 and 50) . the df40t shows 5200-5800.

[Harper]

Got it from the service manual (1999 - 2011. df40 and 50) . the df40t shows 5200-5800.

So is your first question a mistype, or are you really asking about 6500? If the latter, why?

[tommybe1]

yes i am asking about 6500, as stated in the original question I read that your rpm's at wot should be closer to the max (6500) then the minimum (5900), that this would be better for the motor? I wanted to know if this is a true statement and if it was worth getting a different prop? Hopefully this clarifies, if not please let me know. I also see this range 5900 - 6500 in online prop guides.

[tnadeau]

6500 is way too high. Are you using a Suzuki Service manual or a non-Suzuki manual? A quick trip to Suzuki’s website yielded this info: http://www.suzukimarine.com/~/media/...20Brochure.pdf
5800 RPM is the high end. You are correct that you should prop for the high end of the RPM range but 6500 RPM should be verified with Suzuki before you proceed.

[tommybe1]

Thank you for taking the time to reply, I do appreciate it. I'm not sure if my manual is genuine or not, but I did see it listed in prop guides also as stated earlier. The link you sent me was for a DF50A, mine is a 2002 DF50. Again thank you.

[Moonlighter]

Tommy - bottom line: if you can already get 6000rpm at WOT, then you are perfectly propped as is. No need to change anything.

[tommybe1]

Thanks Moon, Its just this motor is so nice I was trying to over protect it I think. I'm glad I got this forum and knowledgeable folks like yourself to ask dumb questions :-)