Evinrude Tilt goes UP but not DOWN

[Majed1965]

G,day All, Hope everyone is well.

Need some assistance.

I have an old Evinrude 50HP (mid 70's) Tilt will go up but won't go down.

The oil level was low, so I topped it up. Still won't go down. When i loosen the tilt valve with a flat head screwdriver the motor comes down. Tightened the screw and tilted up, again it won't come down although i can hear the tilt motor working but the hydraulic lifter doesn't move down.
There are 2 allen key type screws on the outside of the tilt motor. One which is used to top up oil, the other i don't know as i can't unscrew it as the allen type thread is worn out. Tried to open with multi grip pliers, but no good. There is also the flat screwdriver head screw which tilts the outboard down.

I have traced the cable from the trim motor which seems to go directly to the wire harness which connects to the battery. I cannot find any relays connected to the tilt motor. Its not an electrical issue is motor is working.

What could the issue be?

Thanks

 

[boobie]

Re: Evinrude Tilt goes UP but not DOWN

Got a model # ?? And maybe a pic ??

 

[Majed1965]

Re: Evinrude Tilt goes UP but not DOWN

i could not find any relays. I traced the cable coming from the tilt motor all the way to the switch at the front of the boat. No relays just straight cable to the up/down switch.
The manual release screw doesn't come out. Once it is loosened it just spins but doesn't come out.

Please note that electrics is working as the pump is functional up and down but no movement of hydraulics coming down even if i put force on it. Oil is good.
When i loosen the manual release screw the tilt comes down fine. I can't find any relays or soleinoids whatsoever which is weird.

Evinrude 70's outboard model number - 50473M

Tilt No - ESZ 4015 12V
E5


Brand name with some letters not visible - P ES OLINE (these are what we can see, spaces are the letters not visible as they are worn out)

 

[Majed1965]

Re: Evinrude Tilt goes UP but not DOWN

How do you fully remove the check valve to get to the shuttle valve? (maybe its stuck) It seems the check valve screw just keeps spinning and doesn't come out.

 

[bob johnson]

Re: Evinrude Tilt goes UP but not DOWN

the relays are most likely in a plastic black box about 3" and 6" x2" thick. maybe times they are mounted above the carbs...but sometimes i have seen them mounted outside the motor cover, somewhere in the boat!

bob

 

[boobie]

Re: Evinrude Tilt goes UP but not DOWN

This may be a tilt only unit and they didn't have relays.

 

[Joe Reeves]

Re: Evinrude Tilt goes UP but not DOWN

His engine... Model 50473M... would be a 1974 50hp Evinrude.

If a Power Tilt/Trim unit, it would need to be one of the older model units that has a lift cylinder attached to the outside area of each transom bracket. If so, there should be a solenoid incorporated in the "UP" mode of the units wiring... the down mode would be straight wiring directly from the electric motor to the tilt switch. (There are no relays with this type PTT).

If the unit is not of the above design, then I would think is is simply a tilt unit that has both a UP/DOWN mode BUT no trim mode.

However, a picture or two would help.

 

[Majed1965]

Re: Evinrude Tilt goes UP but not DOWN

Hi, thanks everyone for your replies.

I believe it may only be a TILT system. There is only 1 hydraulic arm on the starboard side of the engine.

Some have told me it could be the expansion relief valve stuck. Not sure how to check or fix this.

 

[Majed1965]

Re: Evinrude Tilt goes UP but not DOWN

Hi, thanks everyone for your replies.

I believe it may only be a TILT system. There is only 1 hydraulic arm on the starboard side of the engine.

Some have told me it could be the expansion relief valve stuck. Not sure how to check or fix this.

 

[Fed]

Re: Evinrude Tilt goes UP but not DOWN

I remember reading a service bulletin put out for old OMCs that had a problem if you left the in the fully tilted position, something to do with expansion of the oil popping a valve.
Not sure if it relates to your exact motor, I deleted it from my computer but maybe someone here knows about it.

 

[RRitt]

Re: Evinrude Tilt goes UP but not DOWN

i think he would have the small prestolite motor with a single small tilt ram.

the manual release is held in place with a retaining clip. The retaining clip is often concealed behind a rubber washer. Avoid using too much torque or wrong size screwdriver on the MRV. The slotted head is easily damaged and not replaceable.

Being that it is a 1974 then the check valves are probably stamped & formed with a brass seat rather than compression fit. The good news is that this type of check valve is immune to the problem of popping. The bad news is that if check valve becomes leaky then it can not be repaired - only replaced.

if the valve body uses 9/16" retaining clips to hold in the check valves then the valve body is repairable. If the clips are 1/2" then the valve body is not repairable.
I think 1974 probably has a 1/2" bore.

If there is oil in the reservoir,
the motor is spinning both directions but the system does not move in either direction .... then the most likely problem is a rusted-out tilt piston. If the motor only spins in one direction then it is an electrical problem. If the motor spins in both directions but the system only moves in one then it is a valve body problem.

gl

 

[Joe Reeves]

Re: Evinrude Tilt goes UP but not DOWN

I remember reading a service bulletin put out for old OMCs that had a problem if you left the in the fully tilted position, something to do with expansion of the oil popping a valve.
Not sure if it relates to your exact motor, I deleted it from my computer but maybe someone here knows about it.

Fed..... That had to do with the PTT units that sit inside of the two transom brackets... the type that had two trim rams and one tilt ram. If trailering the engine in the up position and not using the lock down trailering bracket, that allowed the engine to be jumping up and down which over loaded the fluid beyond the 1700 psi that the oil pump is capable of exerting.... as follows:

(PTT Hydraulic Lockup)
(J. Reeves)

If the engine has been trailered without having both of the trim rams pulled in, or trailered without even having the engine being supported by the trailering support, it is possible for the PTT to encounter a hydraulic lock up. The slight up and down motion, when trailering allows over 1700 psi of oil pressure to build up on the wrong side of the oil pump. Since the oil pump cannot exceed that 1700 psi, the unit is effectively hydraulically locked into position (the elec motor runs and does nothing).

The proper method for trailering is to have the engine in a full tilt position and resting on the trailering support bracket, then have both trim rams pulled in to a point where the engine makes a jerking motion. At this point, immediately take your finger off of the PTT trim switch. Now, quickly and sharply, tap the PTT up button. This removes the vast majority of down hydraulic pressure but at the same time, the engine is solidly locked into position and cannot rock up and down.

(The Cure)
Have the engine in the up position and supported so that it cannot fall. Look straight at the PTT assy.... you will see what looks like a large slotted screw on the port (left) side of the PTT assy, but which is in fact a check valve. Remove that valve and what you find inside which is a shuttle valve, and a spring on each end of that shuttle valve.

After you've removed those items, look straight inside of that chamber. You'll be looking at the reverse side of another check valve. Look at the hole in the backside of the valve you removed. You will need a punch that will fit inside of that hole.

Now, place the punch inside of the hole in that check valve that is still in the unit, and tap it rather sharply with a hammer. It will take quite a rap but the idea is to unseat the valve to release the hydraulic pressure. Watch your eyes as when you do release the pressure, it will have a tendency to spray out somewhat.

After releasing the pressure, reassemble the shuttle valve, springs, and outer check valve. Fill the oil reservoir with PTT fluid, having the engine in the extreme full tilt position. That's it.

Not this member's problem but worth mentioning just in case someone else might encounter it.

 

[RRitt]

Re: Evinrude Tilt goes UP but not DOWN

joe, there is actually a simpler cure. put blocks under then engine and loosen the tube nut. the engine falls onto blocks and pressure goes to zero. if the blocks are tight enough then only a few drops of fluid come out. if there is a large gap between blocks and engine then you'll want to have a drip pan and rag handy.

 

[Majed1965]

Re: Evinrude Tilt goes UP but not DOWN

thanks everyone for your assistance.

For some reason the check valve screw doesn't come out. When i loosen it with a flathead screwdriver the outboard tilts down but the screw then just keeps turning but doesn't come out. Do i try and force it out or is there a trick to removing it as i cant seem to get it out to get to the shuttle valve and beyond.

 

[RRitt]

Re: Evinrude Tilt goes UP but not DOWN

First, let us assume that your tilt pump has a 3-1/2" round base and not the 4-1/4" round base.

why do you want to remove the manual release? It is even more difficult to repair than a check valve. OMC lists the part as no longer available. so what good comes from removing it?

if the manual release is directly below the check valve then it is held in place by a retaining clip. you have to remove the retaining clip, carefully clean out debris, and then pull out with a good pair of snub nose pliers (after backing threads out all the way). this is the most common version used on johnnyrudes.

if the manual release is on the end of the check valve then you should not mess with it. replace it or send it off for professional rebiuld. there is a cam and pushrod inside. the manual release will not come out until the valve body has been disassembled and put back together without the pushrod. with pushrod removed, the lobed check valve can be removed and the valve body rebuilt. IF the lobed check valve has a stamped and formed seat, then it has to be replaced with a later model check valve (non lobed) and you will lose the manual release function.

Pictures would help. come to think of it ... I used to have an E/J tilt pump in the shop. It was the 9/16" bore model and I used it to test check valves. I eventually got so good at repairing the check valves that individual check valve testing was waste of time. I never sold it so it still has to be out there in one box, bin, bucket, or other. If you reach the end of all other options, send me a pm and I'll go hunting for it.

 

[Majed1965]

Re: Evinrude Tilt goes UP but not DOWN

I took the boat out today for a quick fishing session and thought i would lower the outboard by loosening the manual release screw. Once in the water for some reason the tilt started to work again. It would now go up and down.

Very weird. Could it be the 1/2 hour drive to the boat ramp and the numerous bumps along the way fixed the problem.

Again, thanks everyone for your input.

 

[boobie]

Re: Evinrude Tilt goes UP but not DOWN

How cold was the water ?? Anyway, sounds like the bumps did it.