1978 johnson 115

[cds11]

just picked up a 1978 Johnson 115 that has 140 psi on all cylinders. just got a few questions before I put it on the boat
.

1. it doesn't have power trim but I'm getting a 1977 Johnson 115 parts motor that does have power trim, can it be easily adapted to power trim?

2. this is my first non direct oil injection motor, what is the best oil to gas ratio?

3. I found the grey wire in the controls for the tach but no power and ground. wheres the best place to get them from?

 

[V153]

First off. Are you sure it has 140 psi per hole? Or did somebody just tell you it was ...

1. I think it will, but '77s kinda a grey area.

2. 50:1

3. Should be a 3 pin connector on backside of the control box.

 

[flyingscott]

The 1978 controls may have a plug on the control box for the tach. The T/N/T from the 1977 may or may not fit on the 78 because that was a transition yr. 50-1 will be the fuel/oil ratio

 

[trailking82]

1978 was a big transition year for both the remote and the power tilt and trim, post a picture of your remote, the 1977 and earlier had a grey wire taped inside as well as a positive and negative leads off the ignition that came out of the bottom. 1978 through the 80's had an external plug for the tach leads.

The power tilt and trim from a 1978 to late 80s will work, 1977 and earlier presented differant configurations most notably the trim pump was mounted on the starboard side of the transom bracket, 1978 and later was mounted within the lifting rams in the transom bracket.

I suggest going to the evinrude parts website, knowing your model number you can cross reference parts from various years.

http://shop2.evinrude.com/Index.aspx..._id=0&siteid=1

 

[V153]

Orig '77 trim motor will be 3 wire vs later years.

 

[cds11]

great info guys! and fast! thanks for the help! I did the compression check myself and couldn't believe it, I bought it from the original owner. the only wire that is able to be connected to in the control box is the taped grey wire. I was getting the 77 motor just for a parts motor with hopes of using the power trim, so you think it would even be worth getting if its not the same? is the lower unit the same? its only 150 bucks and one cylinder has low compression.

 

[trailking82]

I would say for $150 it would be good for parts, lower unit, ignition system should be the same.

 

[trailking82]

The trim could be adapted to the 78, you would have to remove the entire transom bracket.