Replacing Impellers/water pump on a 1977 Evinrude 70 hp Mod # 707739

Bubbasboat

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I am going to hopefully finally buy a motor for my 16' boat. I am looking at a 70 hp this time. It's an Evinrude, 1977, 70 hp, mod #707739, (two model #'s that year 70773/70779 as listed in engine ref chart.) The motor has sat for three years. Plan on doing some carb work, not sure how much, maybe completely rebuild them. Carb work is no problem. I also want to replace the impellers/water pump per recommendations from many people. I have better than average mechanical skills, but I have limited shop space so would have to work on this in my driveway. I have never done this type project before.

Finally, my question; How difficult is this project and is it one that could be done in a driveway by someone with a reasonable set of skills?

1977 70 hp evinrude 2.jpg
 
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boobie

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Re: Replacing Impellers/water pump on a 1977 Evinrude 70 hp Mod # 707739

The first thing I would do is get an OEM factory service manual. It will also help you when you have other probs with the motor.
 

Bubbasboat

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Re: Replacing Impellers/water pump on a 1977 Evinrude 70 hp Mod # 707739

Yes, a manual makes perfect sense. I looked at the link provided. $30.00, worth every penny!! I will also take your answer to imply this could be done in a driveway. If that's not so, please correct me!!

The first thing I would do is get an OEM factory service manual. It will also help you when you have other probs with the motor.
 

boobie

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Re: Replacing Impellers/water pump on a 1977 Evinrude 70 hp Mod # 707739

Yes it can be done in a driveway. Down here in FL we do a lot work outside all the time.
 

Bubbasboat

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Re: Replacing Impellers/water pump on a 1977 Evinrude 70 hp Mod # 707739

Here in Colorado, as we say, "Spring time in the Rockies". Overnight we can go from 76 deg to 3 ft of wet heavy snow!

Not having done this before, how much time should I allot myself, a day or?

Yes it can be done in a driveway. Down here in FL we do a lot work outside all the time.
 

boobie

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Re: Replacing Impellers/water pump on a 1977 Evinrude 70 hp Mod # 707739

You being new to this, I can't really answer that. Good Luck.
 

Bosunsmate

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Re: Replacing Impellers/water pump on a 1977 Evinrude 70 hp Mod # 707739

Id take about an hour or so and im no professional, thatd be having a cup of tea during it too.
So long as you have all the sockets/spanners around and you arent looking all over your place for the right sized sockets then about three hours should cover it for your first time.
Just make sure you undo the shift shaft first, you dont want the motor being hung up by that.
 

boobie

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Re: Replacing Impellers/water pump on a 1977 Evinrude 70 hp Mod # 707739

Tea hell, how about a beer ??:laugh:
 

bonz_d

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Re: Replacing Impellers/water pump on a 1977 Evinrude 70 hp Mod # 707739

Just yesterday I pulled 2 and reinstalled one in about 2 hrs. Changing the water pump probably would have added another 1/2 hour. Then after I test the one I put on I'll pull it again and put the original back on.

Not a hard job as long as the bolts are not all corroded.
 

dodgeman67

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Re: Replacing Impellers/water pump on a 1977 Evinrude 70 hp Mod # 707739

You will be fine
 
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boobie

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Re: Replacing Impellers/water pump on a 1977 Evinrude 70 hp Mod # 707739

Dodgeman, It's also not nice to hi-jack a thread. Read the rules at the top of the forum. Gets less confusing.
 
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