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Tilt issues on '79-'83 mercury 70hp

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bgrizzle321

New member
Ok, so first of all i do not have the serial number for this engine which is making **** so difficult. Looks as if it has been removed. But it is for sure a 1979-1983 mercury 70 hp outboard with no i repeat no power trim, as every stupid manual and diagrams have been showing me motors with power trim, this one does not!!! It has two shock absorbers on the transom mount and swivel assembly though. Those shock absorber are one of my issues, as i think they're shot, definatly the bushings, and apparently i cant find those anywhere. Also, my main conern is, the reverse lock. Ok, so i was able to tilt the motor manually because its manual tilt, not powered trim. But i cant seem to figure out why or how the reverse lock engages the tilt pin on the transom mount bracket, it comes down to it, but dont latch on. How does the motor latch on, isnt it suppose to click in place? Im so confused about this. And so how am i suppose to raise and lower the motor after launch and before loading back on trailer?? Do i have to manually reach down and insert and remove the tilt pin? Im new to this but im winging it, and im figuring things out little by little, but its driving me nuts! And i cant find any info on the internet about these non power trim tilt units!! Everyone seems to think or show power trim units, and mine is not! I dont know if i have a super rare model of this engine or what but damn! If anyone can help me out i have some pics on my phone, but im on desktop at work right now. Please someone help me figure it out. Thank you.
 
Those shocks are to prevent the motor from flying out of the water if you hit something and work with the mercury switch on the block which momentarily cuts the ignition. The reverse locks hold the motor down in N and R and if you shift into F it releases, if it's always locked down the cam in the lower unit is not installed correctly.
reverselockoperation.jpgDon't know what stupid manual you're looking at but this is from the Mercury one.
 
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So you have a " stupid " manual and you have some colorful language for your motor.----And your motor is not rare either.------Facts, when properly set up the tilt lock releases when motor is shifted to FORWARD gear.-----Up to you to check this out and repair as needed if it does not work like that.
 
Quicksilver said:
Those shocks are to prevent the motor from flying out of the water if you hit something and work with the mercury switch on the block which momentarily cuts the ignition. The reverse locks hold the motor down in N and R and if you shift into F it releases, if it's always locked down the cam in the lower unit is not installed correctly.
View attachment 22797Don't know what stupid manual you're looking at but this is from the Mercury one.
Click to expand...

Thank you Quicksilver! Thats exactly it and what i was looking for. Sorry for the rant about manuals not any one specifically just mainly overall through google search. Spending alot of time looking but not finding. Very frustrating. So what you guys are saying is basically to lower my engine into water just flip the tilt lock on the side and then push down from the top of the motor and have the lever in forward so that the reverse lock will be able to go and grab the tilt angle pin? And then only in neutral and reverse the lock will grab the tilt angle pin? And the shocks are basically for the forward motion of things? Like it doesnt really hold the pin in forward? Im gonna post some pics here in a sec. I need to go out and check again to see what it all does but thatll be tomorrow. Thanks again!
 
Haha sorry for the rant again. I never called the motor stupid or anything just all the search findings i have found. But thank you. Im a newbie so i dont know alot about this stuff. Im mechanically inclined dont get me wrong i have tons of auto experience just new to marine.
 
Forget the auto experience - an outboard operates in a different manner (2 stroke with oil 50:1 in the gas) and environment, you should buy the Manual ; Merc Part Nr. 90-75512 and look for a parts list, at some time you'll have to replace the waterpump impeller and gear lube. Maybe you should check/replace these items now.


  • The serial number was on a plate riveted to the port side of the swivel bracket.
  • Serial numbers 4571652 through 4825248 are 1977 models.
  • Serial numbers 4825249 through 5128279 are 1978 models.
  • Serial numbers 5128280 through 5579016 are 1979 models.

 
well, I was already planning on changing out the lower gear oil. I'm about to go do a test start here in a little bit. we'll see what happens. thank you guys
 
Ok, so quick update, didn't get the test start done, but I checked the operation of the reverse lock mechanism, everything is working properly there so that is good. I think I fully understand how that works now, thanks to you guys. Thank you very much for stopping me from going insane. Also, I pulled the plugs, they're clean surprisingly for sitting for a few years, and the carb looks clean. Monday I'm hooking up new fuel line, gas tank, and battery. And i'll see if it runs.
 
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