I checked the model number again and looked it up online and you are right, it’s a 1977 Evinrude. The motor has been painted over except for the transom clamps and tilt/trim assembly, so initially, when I couldn’t find a model number, I assumed it was a Johnson with the white remote control, but the brand doesn’t really matter. The model number is 85799S,so it’s an Evinrude, and I mistakenly took that to be one of the earlier model number formats where the year was the “79” in the number – Sorry! The model number riveted plate is on the port side of the motor on the transom mount, and hard to see it’s there with the motor tilted up.
Yes it has externally mounted trim and tilt components. The cylinder on the port side appears to be just a shock absorber – no hydraulic lines going to it. The hydraulic cylinder and the pump are both on the starboard side. Photo below.
I saw that manual relief valve screw and took it out a couple days ago, but didn’t know its function – ran the trim motor and nothing came out or appeared to pump.
The motor does not sound like it’s struggleing at all in either direction, sounds like it’s spinning very freely, but when it would only run in one direction (down) with the switch wired wrong, my neighbor said he ran it and after a bit, the sound changed, so maybe something broke at that time. This was before he took the line off and got any fluid out.
A couple days ago, I had that manual relief screw you mentioned out and ran it but didn’t know what it was for. Good to know what it’s for now – Thank you!
The line going to the top of the cylinder has no fluid coming out when operated in the down mode – so it’s likely the motor is not coupled to the pump as you suggested.
When I look at the exploded view at marineengine, the pump is the “Prestolite” version.
Today, I just went and took the photo below, and, without doing anything more to it, tried the in/out switch again and something new! While the motor runs now, there is an erratic rattle sound, that erratically comes and goes, like two pieces of metal sharply clanking/rattling, so I suspect something is broken or has come loose. Your comment about the coupling from motor to pump comes to mind, so next, I’ll take the motor off the pump and see what I find. The exploded view at Marine engine may help.
I have found no external leaks.
It’s raining today, so I’ll likely get to it agian tomorrow and hopefully find the problem .
Thank you again!
Dave
PS: Before doing all this, are you completely sure that you are getting that manual relief screw seated completely in the unit, sometimes these things can be tough to turn…