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Old 28-05-2010, 05:39   #16
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Charlie and Spindrift, what are your serial numbers? do you have the same transmissions and gear ratios?

I doubt fuel is the problem. You can reach 3000 RPM in reverse.

A MaxProp is geared internally IIRC. a pitch change large enough to drop RPM that far is doubtful.

I'd focus on the transmission
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Old 28-05-2010, 08:33   #17
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As a seperate question but relevant to the thread does anyone know if the settings on a Max Prop can change once the prop has been installed?
If you have the "Classic" model, the prop must be disassembled for pitch setting to change. Virtually impossible otherwise. I suppose a "Variable Pitch" model's settings could change inadvertantly, but it seems highly unlikely.
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Old 28-05-2010, 08:48   #18
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Sorry to be a thread stealer here. I have the classic Max Prop. I noticed the difference when I changed the pitch. I had replaced my Yanmar 4JH3E with a 4JH4E and thought I should change the pitch. When the engine was installled we didn't pull the boat out of the water so I didn't change the pitch to match the recommendations of Max Prop. The original setting worked better so this time when I pull the boat I will return to the original settings on the boat.
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Old 28-05-2010, 08:57   #19
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When the engine was installled we didn't pull the boat out of the water so I didn't change the pitch to match the recommendations of Max Prop. The original setting worked better so this time when I pull the boat I will return to the original settings on the boat.
Any Max Prop can be adjusted while the boat is in the water. PM me if you want more info.
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Old 28-05-2010, 09:15   #20
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Thanks FB. I'm pulling the boat in a month or so anyway.
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Old 28-05-2010, 21:45   #21
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Mathematics say more pitch more speed. One just needs the HP to push it over hull speed. A 4JH4E only has about 55 HP, which is not a lot for a Warwick 46 displacing 14 tons.
G'Day Del,

I believe that the OP reported that he still got the same boat speed at 2400 rpm as before the problem started, just took a greater throttle setting to acheive the rpm's. Thus, to me it does not sound like a change in pitch.

Cheers,
Jim
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