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Powerhead Transplant 115 V4

J

johnhoc

New member
Hi All, I have a poser for all the experts out there. I have a 1975 115hp Evinrude powerhead and a 1980 something complete lower unit excluding the powerhead. My question is, is it possible to mate the two, I have attached a pic which clearly shows the differences between the 2 mounting faces? The exhaust seems OK, as does the water intake. On the pic, holes marked 1, 2, 3, 4, 7, 8, 9, 10 all line up but 5, 6, 11, 12 do not. Is this a problem? You may well ask why I would even contemplate this. The lower unit of the 1975 model, especially the gear case is shot. Hardly any skeg left, and the cavitation plate looks as if a great white got hold of it. Also, there is no trim 'n tilt. The younger version, on the other hand has trim 'n tilt and is in very good condition - needs a service and water pump service, otherwise good. The powerhead runs like a sewing machine, compression is 140psi all round. Has anyone ever attempted this, or am I wasting my time? Any advice will be welcome.
 

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You are right -it is a waste of time.----You might be better off looking into the shift rod conversion and fitting the 80 lower unit on the 75 model.
 
Last edited:
racerone said:
You are right -it is a waste of time.----You might be better off looking into the shift rod conversion and fitting the 80 lower unit on the 75 model.
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Maybe I didn't make myself clear, that is exactly what I want to do, put the 75 powerhead on to the 80 lower unit. What is the shift rod conversion?
 
The bolts do not line up , so it will not fit--------You might be better off looking at fitting the 80 lower unit onto the good running 75 midsection.------YOU will need to look at / research switching the shift function around.--------The 75 went to forward with a down motion of the shift rod and the 80 version shifts to forward with an up motion.----Sorry I can not write a book for you on how to do this.
 
Thanks racerone, it was a long shot anyway! As a mech. engineer myself, it didn't "feel" right for me, just wondered if anyone had attempted this before. I have a complete mid and lower section including t'nt and lower cowling as well as the cover. I think I will rather try to find a powerhead that is compatible, which I believe is from 1977 onwards, can you confirm this? Unfortunately I cannot swop the lower units, as the 'old' unit is a 25" shaft and the one I want to use is a 20". My boat has 20" transom. There is a long history, but I will not get into it, suffice to say that there are snakes out there that will destroy anything that is not theirs. Thanks again for your contribution, appreciate it.
 
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