Shaft lenght

[fsds123]

How do you determine the shaft length of the following motors?
1979 115hp V4 model # 115999r
1977 115hp v4 model # 115793s

And when looking for a replacement powerhead for the 1979 model...how do I tell what shaft length motor the powerhead came off of?

 

[tashasdaddy]

Re: Shaft lenght

if you are thinking of combining the motors. they have different lower units. there was a change in 1978 from hydro-mechanical shift to mechanical shift. i thing the splines on the drive shaft are different. and shift linkage will not work on the other.

 

[fsds123]

Re: Shaft lenght

I understand they are not compatible, but am trying to find out how to determine the shaft length by looking at the powerhead model number...I am trying to find a replacement powerhead for my 1979 model (needs to be a 1979+, I understand that ) , but am wondering if I also need to watch out for what shaft length the powerhead came off of, and how to tell.

I was asking about the 1977 model for someone else.

 

[ezeke]

Re: Shaft lenght

The 1977 came in 20". The 1979 Evinrude had choice of 20" (115999) or 25"(115990). The 1979 Johnson 25" has a "X" in the model number.

If you can find one, the 1977 25" X model 115HP was built on the 1977 140 base which is the newer gearcase. I've never seen one.

 

[fsds123]

Re: Shaft lenght

Thanks. One more thing...does that mean only powerheads that came off 20" lower units will work?

 

[ezeke]

Re: Shaft lenght

On your 1979 motor, the powerhead could be virtually any of those from 1978 on, 115 or 140. I would find the 1980's model with the new carburetors and primer solenoid if it were mine.

 

[fsds123]

Re: Shaft lenght

So I don't have to pay attention to shaft size?

 

[ezeke]

Re: Shaft lenght

The top of the driveshafts are the same. Your midsection/exhaust housing controls what will fit on it.

 

[fsds123]

Re: Shaft lenght

Ah, very good. Appreciate the help.