STRINGER TRIM DOES NOT WORK PROPERLY

[Simmity]

Hi,
I just got my first boat 1984 120hp Johnson omc I/O.
I don't know much about boats or engines.
my issue is, on the throttle handle the up and down trim buttons,
when I push the down button I hear like a motor running sound. but nothing moves.
when I push the up button I hear a click noise and nothing moves.
both noises come from the rear.
The trailer trim on the other hand works fine. up and down.
can anyone help??
thanx

 

[oldglastron]

Hi there,
do you have a switch at the throttle and one at the stern? The click noise sounds like the solenoid on the trim unit in the boat may not be working correctly. I would check the wiring for corrosion then test the solenoid. Since the motor does run when switched down, the fluid in the unit could be low or there is air in the system try the bleeding procedure. There should be bleed screws on the rams, If it lefts up and down though with the switch on the stern I would likely say you have a electrical project ahead of you. Some of the other guys can give you more info but here is a quick place to start.

 

[Simmity]

I have the up and down button on the throttle handle, and the just below the handle is a trim selector switch, which I call the trailer trim, it works fine.
I don't have a switch in the rear. Are you saying the trailer trim should be in the back? The trailer trim moves up and down fast.

 

[GA_Boater]

Welcome aboard.

Moved this to the OMC section.

I'm guessing you have an OMC Stringer drive. Is there a large rubber diaphragm on the stern with the drive in the center?

If I guessed right, you have an electric trim motor that raises and lowers the front of the engine to trim the drive. Trailer tilt is another electric motor outside of the boat on the lower port side under the drive.

Neither of the electric motors have any hydraulic pumps. Tilt and trim is mechanically driven by the electric motors.

We really have to identify exactly what you have before offering much advice.

 

[oldglastron]

There are different styles depending on years, Just to verify this is a OMC stern Drive correct not a outboard? On the outboards they have two smaller trim cylinders built into the unit and then a large cylinder that handles trailer mode. Which by the way you are correct that is for the trailer. Its does sound like the switch is working It more sounds like a electrical issue at the solenoid and or maybe some air in the system. It could be a weak trim motor as well but if the tilt works I doubt it. See how bad the wiring looks, if the jackets coming off the wires or it looks burnt that may be the answer to your question trim motor should be to one side of the motor if it has power steering it will have two units. make sure your after the correct one.

 

[Simmity]

you are right about the large rubber diaphragm, but I don't have any switch in the stern, I think that switch is mounted about 8 inches below the throttle handle

 

[Simmity]

which I assume is the trailer trim, your saying that's a separate motor, which that works fine.
so the problem is with the fine trim
where do I begin, I have no clue about this.

 

[GA_Boater]

I just got my first boat 1984 120hp Johnson omc I/O

He did! The Cobra came out in 1986. Lets not confuse the guy with all this talk of outboards or Cobra tilt and trim systems.

 

[oldglastron]

ignore the stern switch I thought you had a outboard look at the moderators post. with the electric motors on the unit and more info on exactly what you have.

 

[Simmity]

its an inboard outboard, and no power steering

 

[GA_Boater]

you are right about the large rubber diaphragm, but I don't have any switch in the stern, I think that switch is mounted about 8 inches below the throttle handle

Now we know you have a Stringer drive. The trim switch is on the throttle and the trailer switch isn't - It depends on the remote control.

Now we need to wait for a Stringer guy to see the thread. I don't know a thing about Stringers, but we do have some good guys here. Sorry, Simmity.

I'm going to change the thread title slightly to get more attention.

 

[Simmity]

thanx

 

[Simmity]

Hi guys,
I found this info,
If I understand correctly, does this mean the trailer trim has to be DOWN all the way in the water at all times?
and to not use the up and down throttle trim?
read below
Big thanx in advance!
"It is also important to point out what the OMC Stringer Power Tilt system is NOT designed to accomplish.
On other competitive U-Joint driven sterndrives the Tilt and Trim functions are typically combined and are
hydraulically driven with rams used to both lift the unit and provide a few degrees of thrust angle trim.
While this combined method works well on U-Joint driven sterndrives, USING THE OMC STRINGER TILT
FOR THRUST TRIMMING will result in premature wear of the OMC Stringer ball-gears. The tilt
should always be operated in the fully DOWN position under power on all OMC Stringers. The power tilt
can be partially raised (with engine running) underway in shallow areas and ONLY for limited a time. If
this precaution IS NOT observed premature ball gear replacement will be required."

 

[southkogs]

Welcome aboard Smitty. On your Stringer, you have two different systems - one for tilt and one for trim.

Tilt occurs at the quadrant gear of the stern drive (port side just behind the boot). That is for raising and lowering the drive. Stringers are designed to run in a full down position, otherwise (as stated above) you'll tear up the ball gears between the intermediate case and the upper gear case. You can run with the drive tilted up for shallow water occasionally, but keep it to idle/no-wake speeds.

The tilt motor is on the inside of the intermediate housing (inside the boat) on that same port side.

Trim occurs at the front of your engine. There should be a jackscrew on the front of the engine with an electric motor at the bottom (port side of the mounts). The Stringer trims the entire driveline all together - not just the stern drive. You'll need a manual to break into that jack screw, but if the motor is turning and nuthin' is moving then that's what's goofed up.

 

[GA_Boater]

When running the engine, the trailer tilt should be down all the way. The only purpose of tilt is to lift and lower the entire outdrive to clear a ramp when launching/retrieving or keep it off the road when towing. Tilt has almost 90 degrees of movement.

Trim is used for small adjustments to change the angle of the propeller in relation to the boat which raises and lowers the bow. Since trim raises and lowers the front of the engine, the angle of the ball gears is unchanged and less wear occurs. Using tilt instead of trim causes excessive wear to the ball gears because the gear angle under power is not perfect and adds stress to the gears.

So what the paragraph is saying is keep the drive tilted all the way down on the water and use the trim buttons to make small adjustments to the boat attitude by lifting (trim up) or lowering the bow (trim down).

Hope that makes sense, Simmity.

 

[Simmity]

is the trim and tilt motor the same unit, or 2 different motors?

 

[GA_Boater]

Two separate units. The trim motor is mounted on the front motor mount assembly and the tilt motor is on the lower port side of what's called the intermediate housing assembly.

 

[Simmity]

Thanx guys, I got it now! the trailer "TILT" moves the outdrive up and down.
The "TRIM" actually move the WHOLE ENGINE up and down, that's why it has the rubber gasket is on the transom, to allow it to move everything to move up and down.
What a weird design, is this common on a lot of boats?

 

[GA_Boater]

You got it now. :thumb:

As far as I know, no other manufacturer did it like this. In fact OMC switched over to Cobra drives which are more like Volvo-Penta and Mercruisers. Then they stopped making I/Os all together. Parts for Stringers are hard to come by.

 

[southkogs]

What a weird design, is this common on a lot of boats?

Not so much any longer ... though OMC was a player for a long time. Stringers really had a pretty good run from 1962 all through the early 80s, but ultimately the design went the way of the dodo.

The design can be a little quirky, and parts can be harder to find - but there are some advantages too. I actually like the drive I have on my Silverline - even being the dreaded electric shift