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1981 omc 170stmrcif tilt/trim motor install help

M

Mike_The_Grad

New member
Hey everyone, this is my very first post. I do not own a boat. But I am helping a friend out with his. It's a 1981 omc 3.8l v6 with omc 800 series sterndrive. He got the boat for free on craigslist and he scored bigtime. Engine has new remanufactured heads, runs like a top, interior is in excellent shape. But it's got a few small things that need to be addressed. One of them being the trim motor for the outdrive. The boat didnt come with one. So he ordered one, it looks like the right one. I jumped in to install it for him. Realized that there was another component missing, the hammerblow coupling. Ordered a used one off ebay. $75 later it shows up. Looks like the right part. Now the fun part, installation. Trim motor has gasket, I got some 5/16 bolts and washers from hardware store, greased up the hammerblow clutch, got it to seat into gear drive for the trim, went to install the trim motor and I got it to mate up with the hammerblow clutch. When I go to tighten the 2 retaining bolts. There is still a gap of about 1/4" between the motor and sterndrive mount area. Is there a plate or something that goes between the motor and sterndrive intermediate housing? Do I not have it installed correctly? I definitely felt the two parts seat into the hammerblow clutch and when I try to rotate the motor I can feel spring tension. I know it's not good to force them together as this can damage other parts inside the sterndrive. Any help or advice is appreciated. Thanks for your time.
 
might be a broken bit of the roll pin in there. The roll pins quite often break - the whole shaft and roll pins is like $20 new from NAPA/Sierra.

Here's the most important bit of info though. That system ain't trim. If you trim with it you will junk your ball gears in a few minutes of running. It is only a tilt system for trailering.

Your trim system is the hydraulic engine mounts
 
Thanks for the reminder on the tilt/trim differences. I have to explain that to my friend before he takes it out. Any chance you have a picture or s psrt number for the roll pin? I have very little experience in or on boats. But I am mechanically inclined. I've replace raw water pumps, pulled complete stern drives, rewired some switches, serviced throttle controls, but know nothing of these omc systems. Like I said before this boat did not have a tilt motor at all or any of the components to make it work. I had to lay on my stomach with a 2 foot screwdriver to manually tilt the sterndrive unit. It wasnt fun. After looking online it appears I have the correct tilt motor and hammerblow clutch. But I'm not sure if there are other parts that are required. I also might not have it completely engaged.
 
Mike_The_Grad said:
Thanks for the reminder on the tilt/trim differences. I have to explain that to my friend before he takes it out. Any chance you have a picture or s psrt number for the roll pin? I have very little experience in or on boats. But I am mechanically inclined. I've replace raw water pumps, pulled complete stern drives, rewired some switches, serviced throttle controls, but know nothing of these omc systems. Like I said before this boat did not have a tilt motor at all or any of the components to make it work. I had to lay on my stomach with a 2 foot screwdriver to manually tilt the sterndrive unit. It wasnt fun. After looking online it appears I have the correct tilt motor and hammerblow clutch. But I'm not sure if there are other parts that are required. I also might not have it completely engaged.
Click to expand...

http://www.marineengine.com/newparts/part_search.php?part_num=18-2156
 
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