OMC 140hp with 400 stringer sterndrive lots of questions!

AdamRoberts

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Sep 7, 2024
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Hello,
I'm new to the site and boat mechanics.
Recently bought 16ft 1981 starcraft super sport aluminum with a 140hp OMC engine and a 400 Stringer sterndrive.
I have been reading and learning as I go and am looking for advice on oils for the upper/lower and well the whole thing. Ordered a manual online and waiting for it to show up, but anyone that has experience with these would be appreciated
 

matt167

Rear Admiral
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Sep 27, 2012
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4,149
16’ SS with 140hp will fly.

The guys who know more about them than I do will chime in I’m sure. If it’s still serviceable you’ll find what you need to keep it going. If your boat needs a transom, it might be time to seek out a rotted 3.0L mercruiser boat and convert it ( Late model Volvo just as viable too )
 

AdamRoberts

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Sep 7, 2024
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Transom is actually in great shape from what I can tell.
Had it on the water a few times, engine works great. Ball gears had some serious wear so i have replaced those and seals. Also replaced the tilt motor, suspect the previous owner was running with tilt not all the way down.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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You ordered a factory manual correct? From www.outboardbooks.com?

SAE 30 and 75W90 marine gear lube

Learn to set points and other old-school maintenance requirements
 

southkogs

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Welcome aboard.

Transom doesn't matter as much with the Stringer. As long as it's not taking on water.

'81 should be mechanical shift, so you can use any marine gear lube. You don't need anything particular in it. (Unlike the electric shift)
 

AdamRoberts

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Sep 7, 2024
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Thank you to all!
Sure I'll be sucking up all the info. Be a learning opportunity for sure!
Had it out on the water all weekend and didn't take on a drop of water so far.

Old ball gear was in rough shape, but all new installed now also
 

froggy1150

Master Chief Petty Officer
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Nov 3, 2017
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That is the fill hole. Fill ti there. If you look on the inside of the boat in the same spot you will see a little rectangle cover. Mine didn't have a drain plug so I have to remove that cover and suck old out.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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white paint and that lower are the 78-1980 hydro-mechanical shift stringer vs the 1981-1984 mechanical shift (silver)
 

AdamRoberts

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Sep 7, 2024
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I'm just learning these details as I go about the boat. Was told it was an 81' your imput seems to point to it being an 80'. Thanks.
I removed the gear as I just replaced the tilt motor recently and had to clean service the clutch for it.
Then had the leg off to replace ball gears.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Boat companies use up old stock. Boat could be a 1981 using a 1978-1980 drive they had

When you get parts, knowing the vintage of the drive will be important
 

southkogs

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ON your engine - probably starboard side toward the stern - you should find a metal tag with an ID on it. It could be something like 990245C or more like 140FTHRCIS (depends on the year). You can use that number to determine what the original setup was.
 

oystercracker

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Aug 12, 2020
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3
Transom is actually in great shape from what I can tell.
Had it on the water a few times, engine works great. Ball gears had some serious wear so i have replaced those and seals. Also replaced the tilt motor, suspect the previous owner was running with tilt not all the way down.
Do you know if the engine tilt and the outdrive tilt share the same motor?
 

oystercracker

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Aug 12, 2020
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3
2 separate motors and control buttons
I get the same response from both switches, draws power on the voltage gage, but neither move. The motor for the engine tilt was replaced about a year ago. I have only had her in the water about 3 times in the last 3 years. I replace the solenoids at the same time I replaced the tilt motor. My hunch is something electrical...I bought s new battery and the engine turns over, some gages aren’t working also...I am thinking a ground issue....any tips???
 

kenny nunez

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Jun 20, 2017
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Did you replace the solenoids with the correct marine style? Most marine solenoids are “non grounded base”. Also marine solenoids are sealed so they will not create a open spark.
Is there power to the battery side of the solenoids? There are two 50 amp fusees, 1 powers the instrument panel and the other powers the tilt/trim motors. Those things cause a lot of problems because the fuse holders loose their tension and I have had more than 1 of those fuses show good with a test light but still not work. Replace them with 50-60 fusable link wires.
 
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