Is 5400 RPMs acceptable?

J

Jeep Man

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Here's the story. The motor is a 2002 Bigfoot 60 hp on a 20' pontoon. The prop that came with it was a beat up 14x11 and after a few runs I switched to my backup 14x9. This worked fine except it had a tendency to overrev (above 6100) at WOT. I picked up a new prop last weekend and was talked into a 13.8x11 4 blade Merc aluminum prop. Apparently it is suppose to outperform the 3 blade. With a 1/4 tank of fuel and just me onboard, max RPMs is 5400 at a speed of 19 mph on GPS. What can I expect with 4 onboard and a full tank which would be more the normal? Should I have purchased a 13.8x9 4 blade instead or go back to a 14x11 3 blade?
 
jestor68

jestor68

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Re: Is 5400 RPMs acceptable?

As I believe your full throttle rpm range is 5000-5500, I'd say you were in pretty good shape. :)
 
S

steelespike

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Apr 26, 2002
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Re: Is 5400 RPMs acceptable?

It would be better if we had all the performance numbers for these various props.
My info says rpm range is 5500 to 6000 so your too low at 5400.The spare is really close.
You might consider adding a little cup to the 9"
Won't need much.
Do all these props perform normally?
Your 11" calculator numbers are respectable at 22% slip (reasonable for a pontoon).
Maybe have a prop shop remove some pitch
Again if we had the performance numbers for all the props we could tell better
where your at.
 
jestor68

jestor68

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Re: Is 5400 RPMs acceptable?

:facepalm:
steelespike said:
It would be better if we had all the performance numbers for these various props.
My info says rpm range is 5500 to 6000 so your too low at 5400.The spare is really close.
You might consider adding a little cup to the 9"
Won't need much.
Do all these props perform normally?
Your 11" calculator numbers are respectable at 22% slip (reasonable for a pontoon).
Maybe have a prop shop remove some pitch
Again if we had the performance numbers for all the props we could tell better
where your at.
Click to expand...

In 2002 the 60 bigfoot was available as both a 2 stroke and as a 4 stroke. I guessed it was a 2 stroke.:(
 
S

steelespike

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Messages
19,069
Re: Is 5400 RPMs acceptable?

While I'm sure there was a 4 stroke bigfoot unfortunately my info doesn't list one
so my figures are actually from a regular 4 stroke though rpm figures would be the same.
 
J

Jeep Man

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Re: Is 5400 RPMs acceptable?

Sorry, missed that part. It's a 4 stroke efi.
 
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