80hp Mariner prop and pitch question

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wilsontdy

Cadet
Joined
May 29, 2003
Messages
9
My 1983 80hp Mariner is not quite maxing out the RPM it should at WOT. I am using a 23p now and am wondering what pitch to go to, the numbers on the rear of the prop say H 12.5 X 23P, but I can't read the numbers on the side. My serial number is 6468823. Any thoughts?<br />Mark
 
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Hooty

Rear Admiral
Joined
Oct 2, 2001
Messages
4,496
Re: 80hp Mariner prop and pitch question

Just as a rule of thumb, one inch of pitch will change the engine 200rpm. In other words, if you drop down to a 22" pitch, your engine will spin up about 200 more revs.<br /><br />c/6<br />Hooty
 
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phillnjack

Seaman
Joined
Oct 22, 2003
Messages
51
Re: 80hp Mariner prop and pitch question

80hp mariner 23 prop way too big. you aint gonna get no holeshot with that on anything.i have tried lots on my mariner 80 and the best was 19inch pitch. gave a nice holeshot and good mid range and 5500rpm flat out on a 17 ft cabin boat. top speed for me was 45knotts boat weighed 1900lbs dep vee tapering to gull wing. the start was fast enough for deep mono sking and did not give too much bow lift. this engine also likes fins with the power trim its a nice mid range engine that economical due to power to weight ratio. hope this helps ........ phill :cool: :cool:
 
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