Mercury 90hp (1970s) revs high like it's slipping out of gear

M

marcuscarr

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Jul 19, 2005
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I recently purchased an older Ranger bass boat with a Mercury 90hp outboard.<br /><br />When moving at slow speeds the motor seems to run fine. When I throttle up, the boat starts to get a push, then the push stops and the motor revs up to a high pitch.<br /><br />It sounds like driving a stick shift and pushing in the clutch without letting up on the gas.<br /><br />Any ideas what to look at first?
 
L

Laddies

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Sep 10, 2004
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Re: Mercury 90hp (1970s) revs high like it's slipping out of gear

Sounds like the prop hub is slipping
 
Clams Canino

Clams Canino

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Jan 10, 2004
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Re: Mercury 90hp (1970s) revs high like it's slipping out of gear

Yep - mark the prop and it's hub and check for a spin. Not an uncommon problem.<br /><br />-W
 
M

marcuscarr

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Jul 19, 2005
Messages
25
Re: Mercury 90hp (1970s) revs high like it's slipping out of gear

I did a search for slipping prop and found out a little more about the problem. I am so glad that I did not ruin the motor.<br /><br />Thanks guys.
 
timmathis

timmathis

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Re: Mercury 90hp (1970s) revs high like it's slipping out of gear

Time to get it rebuilt!
 
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