1972 johnson 6hp impeller replacement

[mrlatj]

I'm trying to access the impeller / water pump on a johnson 6r72d. I have removed the 4 bolts holding the lower unit, but I can only get less than 1/2 inch separation. How does the lower unit come off?

 

[codykoke]

Re: 1972 johnson 6hp impeller replacement

I believe you may have to remove the powerhead to disconnect the shift linkage. That will allow to Lu to drop

 

[boobie]

Re: 1972 johnson 6hp impeller replacement

Shift it into reverse and pull the lower unit down further. Look into the gap and you should find a coupler on the shift rod. Remove the lower bolt and it should come off.

 

[tx1961whaler]

Re: 1972 johnson 6hp impeller replacement

Shift it into reverse and pull the lower unit down further. Look into the gap and you should find a coupler on the shift rod. Remove the lower bolt and it should come off.

^^ what he said.
The 6 hp also has a pin at the top of the driveshaft that needs to be aligned with a slot in order for the lower unit to completely drop. After disconnecting the shift linkage, rotate the flywheel until the lower unit comes out.

 

[mrlatj]

Re: 1972 johnson 6hp impeller replacement

The shifter did connect at the top of the lower unit. I was able to get it off (finally) and open up the water pump. The impeller was in remarkably good shape. I used a wire brush to clean out the pump housing, reset the impeller and reassembled everything (easier said, than done, considering I had disassembled the lower unit). So in the barrel it went and everything seems to work. I still can't believe how clean the powerhead is. Thanks for your help.

 

[Tim Frank]

Re: 1972 johnson 6hp impeller replacement

Please tell us that you did not reuse the old impeller....:facepalm:

 

[the machinist]

Re: 1972 johnson 6hp impeller replacement

Well I may be speaking out of turn here & not trying to step on anyone's toes, but replacing an impeller just for the sake of doing so in my mind is not justified.

If it is a new motor to you, yes it is a good idea to replace one, but in reference to the one we are discussing here if the impeller looked good AND was still pliable with no cracks, I see no real reason to replace it for a motor of this size/usage.

HOWEVER if this was on a larger ocean fishing motor where you will be offshore many miles & if it (the impeller) went out where you would be paddling until your arms fell off AND put your/your passengers in possible danger, then that is a whole different story.

I just went thru the same thing last week on a 1984 6hp which was new to me. I ordered a new impeller, tore the lower unit off & found my existing impeller was .150" thicker than the new replacement. This motor had sat for 5 years after the previous owner had a bad back injury & became paralized. Upon inspecting the old impeller (which obviously had not been used much) I reused it & feel confident it will function for me many years.

 

[Tim Frank]

Re: 1972 johnson 6hp impeller replacement

Well I may be speaking out of turn here & not trying to step on anyone's toes, but replacing an impeller just for the sake of doing so in my mind is not justified.

If it is a new motor to you, yes it is a good idea to replace one, but in reference to the one we are discussing here if the impeller looked good AND was still pliable with no cracks, I see no real reason to replace it for a motor of this size/usage.

HOWEVER if this was on a larger ocean fishing motor where you will be offshore many miles & if it (the impeller) went out where you would be paddling until your arms fell off AND put your/your passengers in possible danger, then that is a whole different story.

I just went thru the same thing last week on a 1984 6hp which was new to me. I ordered a new impeller, tore the lower unit off & found my existing impeller was .150" thicker than the new replacement. This motor had sat for 5 years after the previous owner had a bad back injury & became paralized. Upon inspecting the old impeller (which obviously had not been used much) I reused it & feel confident it will function for me many years.

Your motor....your call!....
For me, if I was going through the effort to drop the lower unit to get at the impeller and had substantial cleaning of the housing, I'd be putting in a new one....certainly would have one on hand. A LT $20- part that takes a few hours to R&R is going to get changed at my place every time I have the housing opened up.
They not only suffer from total turn wear, but also simple chronological deterioration of the rubber. That is really tough to assess visually.

And nothing in OP's post suggested that he knew the history. There must have been a reason that he was trying to get at the impeller.