Impeller Rotation DIrection Significance?

Frank Howard

Cadet
Joined
Dec 25, 2012
Messages
20
I recently changed my impeller, on my small 9.9 johnson 1977 outboard, and was wondering does it really matter which direction the impeller is positioned in? I put vaseline around the edges of the veins of the impeller, so wouldn't the impeller direct itself in the direction neccasery when I run the motor?
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: Impeller Rotation DIrection Significance?

If you're lucky it will. Run it wot and if it doesn't overheat you're okay.
 

kodibass

Master Chief Petty Officer
Joined
Apr 10, 2010
Messages
864
Re: Impeller Rotation DIrection Significance?

Most of the time they will set themselves but not always, If you do run it wot, do so in forward gear on the back of a boat, not in a barrel and never in neutral ..
 

minuteman62-64

Lieutenant
Joined
Apr 12, 2011
Messages
1,350
Re: Impeller Rotation DIrection Significance?

The repair manual for my motor indicates that, when installing a new impeller, the vanes should be greased and the housing should be installed while rotating the drive shaft clockwise. That takes care of the proper orientation. Running it in may not cause a problem, if done as suggested in previous posts. But, why take a chance?
 

Frank Howard

Cadet
Joined
Dec 25, 2012
Messages
20
Re: Impeller Rotation DIrection Significance?

Most of the time they will set themselves but not always, If you do run it wot, do so in forward gear on the back of a boat, not in a barrel and never in neutral ..

Im pretty new to boating, and engines but whats running it "wot"?
 

Frank Howard

Cadet
Joined
Dec 25, 2012
Messages
20
Re: Impeller Rotation DIrection Significance?

Ahh Thanks! I thought you guys were intentionally mispelling "hot" or "wet"...I know im a bonehead sometimes:facepalm:
 

kodibass

Master Chief Petty Officer
Joined
Apr 10, 2010
Messages
864
Re: Impeller Rotation DIrection Significance?

trying to gain information & knowledge, is a far cry from being a bonehead,, the good news is you came to a wealth of both here on iboats there are some on this site who are absolutely amazing in their skill level, knowledge of outboards, historical information, and many other special marine/outboard related talents.
 

rothfm

Ensign
Joined
Sep 26, 2006
Messages
913
Re: Impeller Rotation DIrection Significance?

trying to gain information & knowledge, is a far cry from being a bonehead,, the good news is you came to a wealth of both here on iboats there are some on this site who are absolutely amazing in their skill level, knowledge of outboards, historical information, and many other special marine/outboard related talents.

Agreed.....To the poster, check out this thread as proof of the above statement! Amazing how fast info gets out there---EVEN ON A 1915 MOTOR!!!
 

Frank Howard

Cadet
Joined
Dec 25, 2012
Messages
20
Re: Impeller Rotation DIrection Significance?

Im still completely amazed at the expertise and swiftness of responses to my questions, Im extremely lucky to have found this forum, and thankful to the majorly informative forum posters
 

renelson

Seaman
Joined
Jan 5, 2006
Messages
64
Re: Impeller Rotation DIrection Significance?

My 9.9-35 hp manual says "...install the impeller into the impeller cup. Sharp edge of cam slot is leading edge during rotation." This should give the drive shaft a more secure bite on the impeller with that sharper wedge leading.
 

Frank Howard

Cadet
Joined
Dec 25, 2012
Messages
20
Re: Impeller Rotation DIrection Significance?

Ok I changed the impeller, did all the work vaseline and all, placed the lower unit back and put it on my boat. I just put it in there without calculatin which way it should spin, clockwise or counter and the thing pees like a race horse. :joyous:
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: Impeller Rotation DIrection Significance?

Go buy a Lotto ticket. LOL
 
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