1977 omc trim?

[nickdiebolt]

My friend just baught a 1977 19ft trihull with a 190 omc sterndrive. I am helping him out where I can. I am familar with the hydraulic tilt/trim on newer boats, but this boat has a grared tilt mechanism. I was wondering if it is only made for tilt, and if there is a trim mechanism on the outdrive. If there is no trim, should it only be run in the fully down position? Any input would be very much appreciated.

 

[Boatist]

Re: 1977 omc trim?

Welcome to the board. <br /><br />I am not sure about 1977 but think it is the same as my 1980.<br />In 1980 motor came with tilt useing a gear on the port side of the outdrive. There is also a clutch pack that allows motor to kick up if you hit something.<br /><br />Motor could be manual trim or select trim. Either way trim is done by raising and lowering the front of the motor. Manual trim with a screw to manual raise and lower the front of the motor.<br />Select trim use a motor to turn a jack screw at the front of the motor to raise or lower the front of the motor.<br /><br />So tilt and trim two totaly different units.<br /><br />Tilt for shallow water at idle speed and trailering. Never run at high speed with motor tilted.<br /><br />Trim can be used at any speed to adjust boat trim.<br /><br />My 1980 unit the tilt switch is on the dash.<br />The trim switch in on the throttle handel<br /><br />Hope this helps.

 

[KaGee]

Re: 1977 omc trim?

I would NEVER run the engine with drive in ANY other position than tilted all down. That is unless you want to chew up the ball gears quickly. If you find yourself suddenly that shallow, shut it down, raise the drive and use other methods to get back into deeper water.<br /><br />According to one of the manuals I have, Ford V-8s use the hydraulic trim, with rams located under each front motor mount. The trim switch is located on the throttle.<br /><br />A manual would be a great asset to your friend.

 

[skicat]

Re: 1977 omc trim?

At one time I had the same power set-up. The tilt is used to raise or lower the outdrive. Never run in the up position. The boat is trimmed by actually raising and lowering the front of the engine. You should have a tilt switch and a trim switch. Make sure the tilt motor is sealed properly. Water always seems to get in there and cause the motor to not work properly.

 

[nickdiebolt]

Re: 1977 omc trim?

I checked it out and it looks lke there is no trim on the boat. There is no trim switch and I did not see a manual way adjust it on the front of the engine. It looks as if the motor is mounted directly to the stringers. Is it possible that there is no way to trim the boat?

 

[KaGee]

Re: 1977 omc trim?

Yes, there were some models sold without it.<br />If you can get the model number off of the engine tag, we can look it up and know for sure.

 

[nickdiebolt]

Re: 1977 omc trim?

Thanks a lot for the feedback guys. It was very helpfull. This is a great site