Are a 1981 and 1985 Evinrude 70hp lower unit interchangable?

Hi Everyone,

I'm a new member to iboats and this is my first new thread.

I just recently bought a "fixer upper" boat, with a 1981 70hp Evinrude outboard motor. While taking off my lower unit to clean everything and make sure everything was in working order, I noticed that my drive shaft (not sure if that is the actual name of the part, its one of two rods, one is the prop shaft and I believe this is called the drive shaft?) was cracked on the top where the splined area is...I found a gentleman with an 85 70hp evinrude lower unit in great shape with many new parts. I was hoping that this lower unit could fit into my 81 "upper unit". Does anyone know if this will work? I checked some other parts like the prop shaft and that will fit in those year specifications. Any help would be much appreciated. Thank you!

Re: Are a 1981 and 1985 Evinrude 70hp lower unit interchangable?

According to this chart it looks like there is a difference, but I am sure someone else will chime in and help out.
You could just replace your driveshaft.
http://forums.iboats.com/showthread.php?t=359907

Re: Are a 1981 and 1985 Evinrude 70hp lower unit interchangable?

Thanks for the quick reply...I don't believe iboats sells one for my motor? It looks like it starts at a higher horsepower and newer model..unless I'm searching the wrong part? I was curious how much it would be to buy a new one

Re: Are a 1981 and 1985 Evinrude 70hp lower unit interchangable?

You are going to have to post your model number to get the correct one. Here is the first one I found, you're not gonna like the price.
Post your model number so that we can look up the correct part. Then go to the top of the page to the "Top Secret File" stickey, there is a list of salvage yards there, I bet one of them will have a used shaft.
http://www.ishopmarine.com/ishop/js...CatFilter=BRP&eCatSupFldr=supplier-100-005-EJ

Re: Are a 1981 and 1985 Evinrude 70hp lower unit interchangable?

I don't know exactly what year they changed, but if it looks the same it will exchange.


Here are the different motors ... look right below the transom mount clamp at the difference.

Re: Are a 1981 and 1985 Evinrude 70hp lower unit interchangable?

Those two are from '77 and '79 respectively.....the two motors in question '81 and '85 will look the same as the '79 lower mount wise (last pic).

Re: Are a 1981 and 1985 Evinrude 70hp lower unit interchangable?

If the years of '81 and '85 are correct, then yes, the units will interchange...

Re: Are a 1981 and 1985 Evinrude 70hp lower unit interchangable?

Hi everyone,

Thank you for answering so quickly...I have yet another question...I decided it would probably be best to buy a used drive shaft...they seem to be pretty cheap on ebay...can anyone let me know what other years would fit mine? Also, how many splines is my year? I would know myself, but that is where my shaft is cracked...I appreciate any help i can get.

More specifically, will a 1977 70hp driveshaft fit in my 81?

My motor number is: E70ELCIM

I believe this means 70 horse, 81, 20 inch shaft

Thanks for any input everyone!

Re: Are a 1981 and 1985 Evinrude 70hp lower unit interchangable?

Your spline count should be 4 at the top of the shaft. I'm not sure if the '77 would fit the '81 or not. They have different part numbers in the books. They'd be similar, but there might be some subtle difference that would make them incompatible.