power tilt and trim problem

G

garzaglass

Seaman
Joined
Feb 13, 2005
Messages
54
I have a 1979 75 hp evinrude. I just got it out of winter storage and I cant get the tilt down. It will go up fine but not down. So now its stuck in the up position. When I hit the down button it does hum like its trying to go down but wont move. I topped off the fluid but nothing changes. somebody told me they can freeze up but I don't know how to unfreeze it! it sat in the half way position all winter. don't know if this caused a problem or not. this unit has 2 cylinders with the piston in the middle. I took the wires off the cylinder thing that runs the motor (i think that's the solenoid) and sanded and clean them but nothing changes. I don't think its a wiring prob since I can hear it trying to move the motor down. one thing I did notice is that when I hit the up button the solenoid does a really loud "click" like i think its supposed to but when I hit the DOWN button it doesn't click like that but does hum. I hesitate to think its the solenoid because I just had a new one put on 2 years ago. any help would be appreciated on this.
 
W

wrosales

Petty Officer 3rd Class
Joined
Jun 8, 2007
Messages
90
Re: power tilt and trim problem

It could be the relay. Check in the black box on your motor and switch the relays and see if it will go down and not up. I believe the relays are the same.
 
G

garzaglass

Seaman
Joined
Feb 13, 2005
Messages
54
Re: power tilt and trim problem

what does a relay look like? that might be what I was messing with. there is box with a cylinder looking thing in it that clicks when I hit the up trim button. its not in the engine its in line with the engine wires and just sits in the boat by the back. but there is only one of these cylinder things not 2 so maybe that is not a relay? i thought it was a selenoid. if this is not a relay what does one look like? and where can I find them?

thanks.

I have attacked a pic of what I have been looking at. dont know if this is the relay or not.
 

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J

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,174
Re: power tilt and trim problem

Could be an air pocket in the system.
There is a manual release screw on the starboard bracket, its usually recessed inside a hole, hard to see and hard to loosen without a wrench on a big screwdriver.

Support the leg and screw it out to the stop, lower the leg by hand, tighten screw and raise the leg, do it a couple of times to cycle the air pocket out, then top up fluid. Tighten the manual release valve to 45lbs.

If I can hear the motor humming it tells me its probably alright.
 
G

garzaglass

Seaman
Joined
Feb 13, 2005
Messages
54
Re: power tilt and trim problem

jonesg,
I think I found the release screw your talking about but wanted to make sure. there is a very large flat screw head on the lower left area of the left cylinder. the slit to put a flat head in is about 1/4" wide! I don't have a screw driver to fit that. is that it? and if so is there a special tool for it? also when you are saying leg are you referring to the lower unit? sorry for not knowing but im a little new on the boat lingo.

thanks for your help.
 
G

garzaglass

Seaman
Joined
Feb 13, 2005
Messages
54
Re: power tilt and trim problem

is there anybody else who could add something to help me out? thanks.
 
R

rabeck5792

Petty Officer 3rd Class
Joined
Mar 2, 2008
Messages
75
Re: power tilt and trim problem

could be that the trim check valve or piston is stuck,i seem to remember there was a fix for this. unfortunately it is on the back side of the pt&t unit.
 
G

garzaglass

Seaman
Joined
Feb 13, 2005
Messages
54
Re: power tilt and trim problem

jonesg,
the model# of the t&t or the engine? and where would I find it?
rabeck,
you mean I would have to take the unit off the transom?
 
G

garzaglass

Seaman
Joined
Feb 13, 2005
Messages
54
Re: power tilt and trim problem

i found out the reason i dont have a part# for my t&t is because it must have been put on at some point after the engine was. i am including a pic so maybe that will help somebody identify it. I did find the relief screw and I am able to back it out a bit and get the engine down. I lowered it and got it back up 4 times but it still wont go down with the electric. any ideas?

well i can put a pic on casue its too big and it wont compress anymore. it has one ram in the middle and a cylinder on each side of it. also there are 2 little rams below it for the trim.
 
L

littletunny

Petty Officer 3rd Class
Joined
Apr 2, 2008
Messages
96
Re: power tilt and trim problem

You probably got a stuck shuttle valve.

How mechanically inclinded are you. I would disassemble the unit to see whats going on.

Sounds like your trim motor is ok.
 
G

garzaglass

Seaman
Joined
Feb 13, 2005
Messages
54
Re: power tilt and trim problem

just wanted to thank everybody for their help. I found the release screw and was able to work the motor up and down by hand until it started moving on its own.
 
J

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,174
Re: power tilt and trim problem

Good, it was probably just an air pocket which you cycled out.
That release valve should be tightened to 45lbs torque, thats quite tight.
Needs a wrench on the screwdriver shaft to accomplish.
 
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