Do I need to remove the Powerhead to replace impeller on Johnson 1978 6hp?

[Terry1611]

Do I need to remove the powerhead on a 1978 Johnson 6hp Seahorse to replace the impeller?

If are you familar with this outboard, could you please provide the basic steps for replacing the impeller?

I do have the service manual (and others), but it's not clear on the need to remove the powerhead to repalce the impeller.

Thanks
Terry

 

[iwombat]

Re: Do I need to remove the Powerhead to replace impeller on Johnson 1978 6hp?

No powerhead removal is necessary. Remove the bolts that hold the lower unit on, and then disconnect the shift rod coupler.

 

[F_R]

Re: Do I need to remove the Powerhead to replace impeller on Johnson 1978 6hp?

No powerhead removal is necessary. Remove the bolts that hold the lower unit on, and then disconnect the shift rod coupler.

But before you do that, remove the spark plugs. Then unbolt the lower unit and drop it down a bit. It won't come very far because of the shift rod that needs to be disconnected, BUT in addition to that, there is a pin through the top of the drive shaft that has to come down through a slot. Slowly rotate the flywheel as you attempt to lower the lower unit. When the pin aligns with the slot, it will come down through. At that point STOP rotating the flywheel and don't turn it again till it is back together.

When you get the lower unit off, pay attention to the position of the pin. You need to put it back in the same position for reassembly so it will go up through the slot.

 

[samo_ott]

Re: Do I need to remove the Powerhead to replace impeller on Johnson 1978 6hp?

Sounds like they made things more complicated after the 5.5!

 

[iwombat]

Re: Do I need to remove the Powerhead to replace impeller on Johnson 1978 6hp?

Totally forgot about that %^&$ pin.

 

[Terry1611]

Re: Do I need to remove the Powerhead to replace impeller on Johnson 1978 6hp?

Thanks for the great info...

So after the drive shaft aligns with the slot, it will then slide all the way out? Does the slot go all the way down the motor housing?

The service manual is not real clear about that. It shows how to align the pin with the slot, but the picture has the powerheard removed.

Thanks for the info, I don't want to have to remove the powerhead if it's not necessary.

 

[jwilkey84]

Re: Do I need to remove the Powerhead to replace impeller on Johnson 1978 6hp?

just take the thing apart already. I have found that it can be helpful and handy to take picture of the pieces as you take them apart, so you can remember how they came out. I usually do this with my cell phone because I always have it with me and it requires no film processing, then if I need to look at the pics when it comes time to reassemble, I just get my phone out and look at the pics.

 

[F_R]

Re: Do I need to remove the Powerhead to replace impeller on Johnson 1978 6hp?

Thanks for the great info...

So after the drive shaft aligns with the slot, it will then slide all the way out? Does the slot go all the way down the motor housing?

The service manual is not real clear about that. It shows how to align the pin with the slot, but the picture has the powerheard removed.

Thanks for the info, I don't want to have to remove the powerhead if it's not necessary.

No, the slot is only through about a 1/8" web. The web holds the carbon seal from falling apart.

 

[Terry1611]

Re: Do I need to remove the Powerhead to replace impeller on Johnson 1978 6hp?

No, the slot is only through about a 1/8" web. The web holds the carbon seal from falling apart.

Does the carbon seal come out? Will I need to replace the carbon seal?

Will I need to replace anything other than the impeller and water pump gaskets? I plan on putting in a complete water pump kit.

Thanks for the help. Sorry for the picky questions (I don't like mechanical surprises, I like to know what I'm doing before I do it.)

Thanks

 

[crxess]

Re: Do I need to remove the Powerhead to replace impeller on Johnson 1978 6hp?

You should not need to touch the seal.

If the impeller has been changed before, the pin could be missing or damaged. You must make sure you have a pin in place on installation to compress the spring and load the seal.

Pin is 3/32 x 3/4" long stainless