power trim & tilt

JOHNSON85 · May 3, 2010

I am having problems with my power trimon my 1973 85hp Johnson. Power trim will raise up and down fine when out of water or in neutral, but when i go to throttle forward the motor comes all the way down. Also when i go into reverse the motor want to come up. sometime the motor wants to leak back down. Should i be able to move the trim up and down when in speed? If so it want come up unless im in an idle. Any suggestion.

Joe Reeves · May 3, 2010

Re: power trim & tilt

The "trim" raises and lowers to a 15? mark while underway..... it will not raise or "tilt" all the way up while underway.

If while underway, the engine is forced from its "trim" setting and goes all the way in towards the transom, that could be a faulty manual release valve or low on fluid.

If that unit is the type that I think it is..... the type that has a cylinder on each side, outside of the transom brackets...... if so, there is what is called a "Stand Up Valve" located in the bottom portion of the starboard (right) cylinder. If that valve is faulty, the unit will fail in the manner you speak of.

JOHNSON85 · May 3, 2010

Re: power trim & tilt

Yes it has two cylinders. Only one of them raises the motor up and down. what is the other cylinder used for? Where is the best place to order parts for this motor and other parts? I really dont understand the terms for the location on the boat. I know what the front and the back are called not he sides i am still learning. This is my first boat and i am trying to fix all of the minor things. One more question what should i put in the hyd motor?

Joe Reeves · May 3, 2010

Re: power trim & tilt

he unit takes Power Tilt Trim fluid available at your dealership OR...... some boaters use some kind of automatic transmission fluid. Someone here will jump in and tell you what kind I'm sure.

That port tilt/trim cylinder does have a oil line attached to it but mainly it is to operate a trim gauge on the dash. I suggest you don't get involved with that just yet.

Boat:
Front = Bow
Rear = Stern
Top side edges = Gunnel (sp?)
Bottom center = Keel
Rear portion engine bolts to = Transom

Standing in boat facing forward:
Left side = Port
Right side = Starboard

Portion of engine that bolts to boat = Transom Brackets
Top portion of engine = Powerhead
Long housing that powerhead bolts to = Exhaust housing
Bottom portion of engine = Lower unit

Huge hole in bottom of boat which water rushes in = &*^!#$@$$^*%!!

JOHNSON85 · May 4, 2010

Re: power trim & tilt

Thanks for your help.

Bonus Cup · May 7, 2010

Re: power trim & tilt

JOHNSON85 said:
I really dont understand the terms for the location on the boat. I know what the front and the back are called not he sides i am still learning.

What someone told me along time ago and I still remember it to this day is:
Port is spelled with 4 letters, Left is spelled with 4 letters. It took me a long time when I first started boating to remember which is Port and Starboard until he pointed that out.

JOHNSON85 · May 10, 2010

Re: power trim & tilt

Thanks, that is an easy way to remember that.

RRitt · May 10, 2010

Re: power trim & tilt

you should post a photo of your system. I am thinking that you have power tilt and the second cylinder is your shock damper. In which case it is supposed to go down as soon as you apply any throttle.

JOHNSON85 · May 10, 2010

Re: power trim & tilt

Here are two pictures of the pump and the cylinders. If this true what you say why would it come up out the water when put into reverse? What is the diffrence between power trim and tilt? Just asking because i dont know.

ezeke · May 11, 2010

Re: power trim & tilt

The unit in your pictures is a power tilt system (no Trim).

It was sold at the time as a kit #0172509 and prior to that as part #0172189.

The PT&T was introduced in 1975 and could be used on your motor.

The part of the motor that holds the motor in when the motor is in reverse is not part of the kit.

Fisherball · May 11, 2010

Re: power trim & tilt

Buy a manual for your motor! Well worth the $$$$. It'll help you fix & probably more than fix, it'll help you figure out how each system works. I always like to know the "why" of everything & mine has always answered that for me. It also paid for itself at least 20 times over.

ezeke · May 11, 2010

Re: power trim & tilt

Fisherball said:
Buy a manual for your motor! Well worth the $$$$. It'll help you fix & probably more than fix, it'll help you figure out how each system works. I always like to know the "why" of everything & mine has always answered that for me. It also paid for itself at least 20 times over.

Normally, that would be true, but the 1973 factory manuals have not one word about Tilt systems or PT&T units.

The 1974 factory service manuals do have information on the installation of an improved trailering lock arm system, which includes the reverse locking mechanism.

Joe Reeves · May 11, 2010

Re: power trim & tilt

In reverse, the manual reverse lock lever knob located at the starboard side of the transom bracket must be switched to the locking position. That hydraulic tilt unit will not prevent the engine from tilting up in reverse....... it is designed only to lift the engine and nothing more.

Fisherball · May 11, 2010

Re: power trim & tilt

He still needs a manual on the motor!

emdsapmgr · May 12, 2010

Re: power trim & tilt

The hydraulic cylinder on the left is a shock absorber. In case you hit a submerged object, it is to protect the lower unit. The tilt cylinder on the right is to raise or lower the engine. It will not overcome the thust forces of the engine when the running in gear.

JOHNSON85 · May 12, 2010

Re: power trim & tilt

Thanks guys for all your help. I will be buying a manual for this motor. i am having some issues with it starting like it's no getting fuel. i have a bottle of premixed gas and oil that i spray in the carb. After it warms up it will fire right off everytime, but if it sets for awhile i have to do it all over again. Any suggestions?

ezeke · May 12, 2010

Re: power trim & tilt

It's essential that the choke plates be 100% absolutely closed for a cold start - you will need to take the cover off the carburetors and watch to assure that they are closed and stay closed while you crank the engine.

Also, The 73 engines had an automatic choke function that failed to perform well and most of them were disabled at the time. See the SB by clicking the thumbnail. If the service bulletin was followed, the toggle switch on the remote control should have full control of the choke solenoid and chokes when the switch on the carburetor is set correctly.

RRitt · May 12, 2010

Re: power trim & tilt

JOHNSON85 said:
Here are two pictures of the pump and the cylinders. If this true what you say why would it come up out the water when put into reverse? What is the diffrence between power trim and tilt? Just asking because i dont know.

This is a power tilt system. The shock dampener on left keeps the engine from bucking on hots days when your hydraulic fluid might be little thinner than usual. The lift cylinder on right controls engine angle based on hydraulic fluid from pump. Pump fluid in the bottom and engine goes up. Pump fluid in the top and engine goes down. Lock fluid in place and engine stays put. Inside the lift cylinder is a breakway valve. This cylinder is not designed to lift an engine under power and the breakway valve should open up at around 5-10 HP.

If your engine drifts down from gravity or up when in reverse then it is almost always a worn out check valve (NLA) in the valve body. The valve body is the thing mounted onto very bottom of trim motor. It could also be a rusted out bypass valve in lift cylinder (caused by water in oil). Your trim motor has been serviced before. The cable fitting is pointing in wrong direction. It is no surprise that your valve body might have problems. They usually need service before the motor. Your model with manual release is no longer sold. Check ebay and you should find a rebuild service in the $120-$150 range.

but - oh - before you do anything else. Your manual release screw should be horizontal. It looks turned enough to me in picture. But you should just go ahead and try again with the screw being fully horizontal. You know, just in case.

JOHNSON85 · May 13, 2010

Re: power trim & tilt

Ezeke,

i did take the cover off of the carb to see if the flap is coming down all the way and it is. It dont want to turn over has fast as it does when you dont chock it.

ezeke · May 13, 2010

Re: power trim & tilt

JOHNSON85 said:
Ezeke,

i did take the cover off of the carb to see if the flap is coming down all the way and it is. It dont want to turn over has fast as it does when you dont chock it.

The point is that you are doing with your spray bottle what the choke is designed to do when working properly, which is to enrich the fuel/air mix for a cold start.

If you don't mind using the spray bottle, then I suppoose it does not matter that your chokes are not set correctly.

power trim & tilt

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