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WOT numbers for a 89 57

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bfoulk

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does anyone know what WOT shou

does anyone know what WOT should be on a 89 5.7 mercruiser. its in a Baja Force 216. Thank you
 
4600-4800 RPM I believe is nor

4600-4800 RPM I believe is normal for the 5.7
You should likely be running either a 21 or 23" pitch prop.
Rod
 
"yikes, just bought the boat a

"yikes, just bought the boat and on the test drive rpm was 5,000-5,800. i do see that it has a 19p prop guess thats the reason for the high WOT. it was running 55-58 mph with the 19.. came out of the hole hard though for a big boat"
 
"Bob;
5800 sounds quite high

"Bob;
5800 sounds quite high for a stock Merc, but 5000 is likely OK for short bursts.
Marine engines are not built for high RPM, but rather extended periods at mid RPM high torque loads.
You dont want to be running much over 5000 for any extended period as you will burn a piston, drop a valve, turn a bearing, or something even more terminal.
A 21" prop will lower your WOT by about 300-400 RPM and may be the best compromise.
The 19 will give you better hole shot, and as long as you watch your WOT RPM's may be what you want for skiing, tubing, etc.

Depends on your expectations, but 55-58 MPH is pretty good top speed. What does the boat weigh?
Rod"
 
"according to what i can read

"according to what i can read about it.. its about the 3,000 lb mark empty. 21' long.. im pretty new to boating and had a 20' cuddy with a 470 in it.. and this new one darn near jumps out of the water when ya open the throttle. it runs very well i think.. i think i may get a 21 prop and try it. i thank you for your answers!!!"
 
"I use a tach tester. it's

"I use a tach tester. it's a pulse generator actually. you could connect a shop tach, and compare readings. I think a tach/ dwell meter is pretty cheap to buy at the local auto parts."
 
"5800 is past red line. Agree

"5800 is past red line. Agree with testing it. I wouldn't want my WOT a turn past 4800.

Also... just food for thought, but aluminum props can be repitched within narrow margins by a qualified prop shop."
 
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