Tilt Trim not working 1975 Evinrude 115

[Markoku]

Hi,
I've got a new to me 1975 115hp Evinrude outboard on my 19' Starcraft. This motor and boat are new to me, so I have been taking it slow trying to figure out how this boat runs. As it had been siting for the last 20 years. The motor runs great, but last week I noticed that the motor will not trim up while I'm underway. I got home and took a look at the pump. I checked the fluid, and it seems to have been emulsified with water, It looks muddy. I replaced the hydraulic fluid with ATF and bleed the system, until I got all the air out. On my driveway the motor seemed to tilt much more quickly and smoothly. But today at the lake, it would not stay up. It was doing the exact same thing as last week. It would trim up while going slow. But as soon as I hit 5 knots, it would drop back down with a thud.

I'm looking for advice on what to do next. Is there an aftermarket tilt trim assembly that I could put on this motor? Or can a newer Evinrude system be adapted to fit? This motor is pretty old, but runs great. I'm concerned that if I try and rebuild this pump, I'm going to break something else. I'm pretty new to boat, would this be something a mechanic at a marine could fix, considering the age of the motor?

Thanks for the advise.

 

[Rustywrench]

The first question would be is it trim & tilt or only a tilt system? What you are describing would be normal for a tilt system. If you could post a picture of the system on the motor we would know which you have.
CMC makes a unit you can use to get TNT. Your old unit (if it is TNT) can be expensive to fix today.

 

[racerone]

Does it have 2 external cylinders or just 1 between the mount brackets ?

 

[Markoku]

Does it have 2 external cylinders or just 1 between the mount brackets ?

It has two external cylinders.

 

[jimmbo]

Does it have 2 external cylinders or just 1 between the mount brackets ?

Deleted as OP replied

 

[Markoku]

The first question would be is it trim & tilt or only a tilt system? What you are describing would be normal for a tilt system. If you could post a picture of the system on the motor we would know which you have.
CMC makes a unit you can use to get TNT. Your old unit (if it is TNT) can be expensive to fix today.

Its only tilt. I'm very new to boating and thought that this system was called tilt trim. The motor tilts up on the driveway just fine, I can't push it down or even get it to budge. It will stay tilted up until I let it down. It stayed up all winter. For some reason it only drops when I go above 5 knots. I wonder if it has something to do with voltage to the tilt motor dropping when the RPM's go up.

Also the left cylinder seems to be leaking a very small amount of old, as I can see it on the shaft now and then.

 

[jimmbo]

The old tilt system has 2 cylinders between the brackets, only one is a lift cylinder, the other is a shock absorber. I had posted this earlier but deleted it when you said the cylinders were external.
The lowering of the engine when you apply throttle is normal, it is not designed to hold the engine up at speeds higher than fast idle

A power trim system for that engine would have 2 external cylinders, one on each side

 

[Markoku]

The old tilt system has 2 cylinders between the brackets, only one is a lift cylinder, the other is a shock absorber. I had posted this earlier but deleted it when you said the cylinders were external.
The lowering of the engine when you apply throttle is normal, it is not designed to hold the engine up at speeds higher than fast idle

A power trim system for that engine would have 2 external cylinders, one on each side

Ok, thats great to know. So its normal for the engine to drop at speed. So there is nothing wrong with this motor. I just wish I could tilt it up at speed.

 

[racerone]

The system pictured in post # 6 is a tilt only system.------Does not have capability to trim the motor.----Move that big pin out one hole to change trim angle at speed.-----Perhaps 2 holes depending on boat and water conditions.----You might want to look into a better / safer steering system too !

 

[Markoku]

The system pictured in post # 6 is a tilt only system.------Does not have capability to trim the motor.----Move that big pin out one hole to change trim angle at speed.-----Perhaps 2 holes depending on boat and water conditions.----You might want to look into a better / safer steering system too !

Whats wrong with the steering system. I replaced it from the helm back over the winter.

 

[racerone]

All I see is that steering is NOT going through the tilt tube on the motor.----More pictures will show what you actually have.

 

[jimmbo]

A lot of old boats didn’t utilize the tilt tube for the steering. Using it reduces the stress inflicted on the splash well as that’s where most of the cables were anchored. It also accommodated engine tilting without having the cable moving up and down under the deck

 

[Markoku]

I cant run the steering through the tilt tube. The design of the transom is such that the steering arm hit the left side of the boat. Also I can't steer my kicker either, if I used the tube. So its mounted to knuckle on the inside of the transom.

 

[Markoku]

Here are a few photo's of how the steering is setup. Its been like this since 1965, and seems to work. The transom is pretty shot, so this fall I intend to pull the motor and replace it. When I do that, I'm going to put the motor on bracket, and at that time I'm going to run the steering through the tube.