What is normal RPM for a 4.3L?

NMBuzz

NMBuzz

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Jul 12, 2009
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Can someone please direct me to a place where I can find the specs for a 4.3L Mercruiser- specifically what RPM's I should be turning at or near WOT.

(Currently at WOT RPM's are near 5,000 and the speed is near 40 MPH)

This seems to be too high of RPM's and I am always a little uneasy when running ANY machine WOT...
If I am off base on this, please let me know.

Thanks in advance!
Buzz
 
D

dubs283

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Re: What is normal RPM for a 4.3L?

NMBuzz said:
Can someone please direct me to a place where I can find the specs for a 4.3L Mercruiser
Click to expand...

adults only sticky, mercruiser manuals link

download the manual that pertains to your engine

specs are there
 
NMBuzz

NMBuzz

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Re: What is normal RPM for a 4.3L?

dubs283 said:
adults only sticky, mercruiser manuals link

download the manual that pertains to your engine

specs are there
Click to expand...

God I luv this forum! Thank you for that quick and informative reply!
 
Fun Times

Fun Times

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Re: What is normal RPM for a 4.3L?

Some where on the engine there should be if it is still stock, Or might be a sticker on the engine or flame arrestor that will tell you your max rpm for the engine.
 
dtime

dtime

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Re: What is normal RPM for a 4.3L?

5000 RPM :eek::not sure about the murcuriser but my 91 omc is rated at 42-4600 RPM WOT with a 2 barrel
 
dtime

dtime

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Re: What is normal RPM for a 4.3L?

ASfor the 40 mph i would try a different prop and lower youfr rpms you may be cavataing. i can reach 42 @ 3800 rpms with a 14.2X19 on my 19 foot thundercraft
 
NMBuzz

NMBuzz

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Re: What is normal RPM for a 4.3L?

dtime said:
ASfor the 40 mph i would try a different prop and lower youfr rpms you may be cavataing. i can reach 42 @ 3800 rpms with a 14.2X19 on my 19 foot thundercraft[/QUOTE

The whole prop pitch and size thing just flat out confuses the crud outta me. I thought I was through with algebra in the 11th grade! LOL

Seems there has to be an easier way... I figure I am running about ~500 pounds give or take with fuel passengers, fuel, stuff... I may try to figure this out a little more... I would really like to get my RPM's down, but still have that good hole shot to get a skier up.
Click to expand...
 
fuzzybob

fuzzybob

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Oct 26, 2008
Messages
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Re: What is normal RPM for a 4.3L?

You might want to do a forum jump over to the prop forum..... lots of prop gurus over there. They'll be glad to do the "algebra" for you.
 
dtime

dtime

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Re: What is normal RPM for a 4.3L?

try thishttp://www.propellerwizard.com/SITEPREVIEW/boat_props/index.php? web site
 
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