Johnson 9.9 1977 Impeller

Frank Howard

Cadet
Joined
Dec 25, 2012
Messages
20
My engine has been overheating, so I determined it must be the impeller. Changed it. old one was missing every vein. My question is should the impeller be rotating freely on the crank shaft? I dont want to go out on the water and find that i did a bad job wth the impeller. Any help is greatly appreciated!
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: Johnson 9.9 1977 Impeller

The impeller is held on to the drive shaft by a key, better find it. If the vanes were missing off of the old impeller better find those or else you'll have some overheat probs.
 

tx1961whaler

Vice Admiral
Joined
May 31, 2008
Messages
5,197
Re: Johnson 9.9 1977 Impeller

No, the impeller should not rotate on the drive shaft. There is a pin that holds it in place.
 

Frank Howard

Cadet
Joined
Dec 25, 2012
Messages
20
Re: Johnson 9.9 1977 Impeller

Thanks! After about a half hour on my hands and knees I found the tiny pin and set it in the impeller groove and notch in the crank shaft. I would have completely overlooked that and by the time i relized anything i probably woudlve had to buy a new pin. THANK YOU!
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: Johnson 9.9 1977 Impeller

How about the vanes, did you ever find any of them ??
 

Frank Howard

Cadet
Joined
Dec 25, 2012
Messages
20
Re: Johnson 9.9 1977 Impeller

No, the veins i was speaking of were the ones connected (or used to be) to the impeller, I had bought a new impeller so i just threw the old one out, along with the broken veins.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: Johnson 9.9 1977 Impeller

Before you threw out the old vanes you should have accounted for all of them. If you had a couple of them that got into the mtr cooling system you could have an overheat prob.
 

Frank Howard

Cadet
Joined
Dec 25, 2012
Messages
20
Re: Johnson 9.9 1977 Impeller

Never thought of that, seems like a smart Idea. ill have to remember that next time I swap an impeller. Id like to take those precautions an tallies more often when working on my motor, better diagnosing and less problems.
 

raczekp1

Lieutenant
Joined
Mar 30, 2010
Messages
1,327
Re: Johnson 9.9 1977 Impeller

if some rubber parts of old impeler goes up with water will stay under powerhead or in water cover jacket chanels(there is some holes and impelers will stop water to circulate)
 
Top