Propeller "free wheels". Normal?

H

huntin dawg

Petty Officer 2nd Class
Joined
Nov 12, 2009
Messages
197
I noticed on my 7.5 Merc that when in forward gear the prop will "free wheel" but in reverse it does not. Is this normal? I assume it is to reduce drag when you let off the throttle? I have a Johnson 4.5 that does not do it.

Thanks,
HD
 
G

gss036

Commander
Joined
Jan 18, 2003
Messages
2,914
Re: Propeller "free wheels". Normal?

I would suspect a spun hub if it has one or sheared key.
 
C

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: Propeller "free wheels". Normal?

With the engine turned OFF, shifted into Forward gear, you should be able to turn the prop CW and feel/hear the engagement dogs 'ratchet' as they cam over from one notch to the next. If you attempt to turn the prop CCW then the engagement dogs positively LOCK and you can turn the motor over backwards.

Reverse engagement dogs are straight cut and positively lock both directions.
 
H

huntin dawg

Petty Officer 2nd Class
Joined
Nov 12, 2009
Messages
197
Re: Propeller "free wheels". Normal?

CharlieB said:
With the engine turned OFF, shifted into Forward gear, you should be able to turn the prop CW and feel/hear the engagement dogs 'ratchet' as they cam over from one notch to the next. If you attempt to turn the prop CCW then the engagement dogs positively LOCK and you can turn the motor over backwards.

Reverse engagement dogs are straight cut and positively lock both directions.
Click to expand...

Thanks!

That's exactly what it does. I appreciate you taking the time to answer.

Cheers,
HD
 
Texasmark

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,569
Re: Propeller "free wheels". Normal?

And the reason for the "slip clutch" in F is so that the propeller can turn faster than the engine without throwing you through the windshield.....when decelerating, this is the case and something had to be done to make it a seamless process.

In R, you usually don't go very fast and a locked up prop is not a problem, so there is no clutch.

Mark
 
M

mke039

Seaman
Joined
Jan 4, 2010
Messages
69
Re: Propeller "free wheels". Normal?

I was about to post the same question, but found it answered here. Thanks.
 
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