Impeller Question with Rabbit Ears On

1985 Century Mustang

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When the rabbit ears are on and the engine is running and the temps are normal, does this mean my outdrive impeller is also functioning?
 

Lou C

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Not necessarily
The muffs force water in under pressure
The true test is if the impeller can move water when the boat is in the water.
On mine I usually run the impeller 3 seasons or so. With a 160 stat my running temps are about 160-170.
 

1985 Century Mustang

Chief Petty Officer
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Mar 9, 2023
Messages
532
Not necessarily
The muffs force water in under pressure
The true test is if the impeller can move water when the boat is in the water.
On mine I usually run the impeller 3 seasons or so. With a 160 stat my running temps are about 160-170.

Thanks, I'll be testing it out shortly. I replaced the water impeller last year, hopefully it held up.
 

JASinIL2006

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Unless you ran the engine without a supply of water, the impeller should still be good. In freshwater, you should be able to get at least three or four years out of one.
 

nola mike

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It should be fine unless it was a cheap aftermarket one. Stay with oem impellers . In fresh water I get at least six out of mine .
Ha ha, like those tootsie roll commercials, none of my outdrives has ever stayed together long enough to have a worn impeller, and I replace them whenever I crack open the drive.
 

Lou C

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Impeller life seems more a function of the water you’re in, not salt or fresh but shallow/Sandy bottom vs deep water and also care when loading on & off trailer that you don’t tilt too high. I think the longest I went was 5 years. Cobra impeller very easy to do; don’t have to split the drive…it lives under a cover at the end of the upper gear housing….
 

1985 Century Mustang

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I took her out today and the temps stayed in the 120-130 range, the impeller seems to be working fine. The water temps here in NY are about 76 degrees.
 

nola mike

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No he means what temperature thermostat do you have installed (opening temp)?
 

flashback

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Jun 28, 2002
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I think he meant the thermostat rated temp, if you're stat is rated for 140 then that is the temp it opens.don't matter what the gauge said.
 

Lou C

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160* stat on my 4.3, runs right at 160, might rise to 170 after coming off plane.
Merc can have a 140 (older models) or a 160 (newer models), I'm guessing you have a 140, so that's about the temp you should run at. On your gauge, it should be on the hash mark between 100 and 175, that's probably about 140*
'88 FW instrument panel.jpg
 
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