1985 OMC won't start.....or Tilt

I was just traded an old dirt bike for a 1985 19 ft Starrcraft bow rider with a 3.0 OMC Sterndrive and Shoreline trailer.
The boat?s in pretty good shape just could use a few seats. It ran fine 2 years ago then he upgraded to a bigger boat, last year he went to get it running to sell and turned over fine but wouldn?t start so he had a few people tinker with it, the plugs distributor and fuel pump are new, so he thinks it?s something with the carburetor.

The second issues are the stern drive will not tilt up. The motor for this has been replaced also you can hear the motor engage but it doesn?t lift or lower the stern drive.

Any suggestions?

I am looking for a diagram of this unit. I have owners manual but am looking for more of a breakdown of the parts involved in the tilt unit, there doesn?t seem to be too much to it.

When looking for motor parts for this I have come across 2 choices, I think one is the 3.0 and the other would be for the 2.5 liter?..how do I know which part is what? Is there a number on the motor somewhere?

This is my first boat so I have plenty to learn.

Thanks!

Re: 1985 OMC won't start.....or Tilt

fburke said:

I was just traded an old dirt bike for a 1985 19 ft Starrcraft bow rider with a 3.0 OMC Sterndrive and Shoreline trailer.
The boat?s in pretty good shape just could use a few seats. It ran fine 2 years ago then he upgraded to a bigger boat, last year he went to get it running to sell and turned over fine but wouldn?t start so he had a few people tinker with it, the plugs distributor and fuel pump are new, so he thinks it?s something with the carburetor.

The second issues are the stern drive will not tilt up. The motor for this has been replaced also you can hear the motor engage but it doesn?t lift or lower the stern drive.

Any suggestions?

I am looking for a diagram of this unit. I have owners manual but am looking for more of a breakdown of the parts involved in the tilt unit, there doesn?t seem to be too much to it.

When looking for motor parts for this I have come across 2 choices, I think one is the 3.0 and the other would be for the 2.5 liter?..how do I know which part is what? Is there a number on the motor somewhere?

This is my first boat so I have plenty to learn.

Thanks!

View attachment 162831View attachment 162832View attachment 162833

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To Fburke -

I'm certainly no expert on these OMC's since I have only had mine about 6 months but I've spent 5.9 months working on it, taking it apart, exploring why things don't work and just figuring out things by myself and by scouring this website. Just this week, I took apart by tilt mechanism and figured out why it quit working with a 3 month old tilt motor that should be working. I took the three bolts out of the crescent shaped gear attached to the lower unit, raised that lower unit up and made absolutely sure it couldn't fall on me or my fingers. Then I took off that gear which runs along the crescent shaped gear to raise up the lower unit. On the other side of this gear, I took off the cover to the clutch housing and took out the clutches and center drive. Couldn't get that big brass ring out since there is a big worm drive sitting on it holding it in. Went to the rear of that clutch housing and took off those 3 bolts holding a triangle shaped cover on and removed that obstacle. Now you have to get that silver cap out that the triangle cover was holding in place. I inched it out with a knife point first, then a screwdriver until it was out. This then exposed that wormdrive which was holding the brass ring in place. This wormdrive has a steel rod through its center and all of that slid out the back pretty easy. Once I pulled all of that out, this steel rod had two tiny pins through it making the wormdrive turn. Those two tiny pins were sheared off and jamming the wormdrive preventing it from turning. I ordered a new steel rod and pins, put it all back together, jammed it slam full of marine grease (everyone says its better because you can't keep the water out of this box) and it works! I know I shouldn't be surprised but it feels good when a plan comes together. This takes a lot of battery to go up so keep that in mind once you try to raise it.

Billy

Re: 1985 OMC won't start.....or Tilt

welcome aboard guys:

Fburke: You can see diagrams HERE. Make sure you click on the drop down menu in the upper left and select stern drive. You should be able to locate yours from there.

There's some stamping on the side of the valve cover, is the engine model number not there? Mine is stamped toward the back on a support.

As far as your tilt - if you can hear the drive whirring away (as opposed to just the solenoid clicking), and you can't move the drive up and down by pushing or pulling on it, I'd suggest pulling the tilt motor and checking the hammer coupling inside. It's a shock absorber (essentially) for the tilt motor. There are 4 pieces involved in the coupling: two circular halves, a key and a spring. Be careful getting it out ... they like to jump down your bilge

If the drive will move when you push or pull on it, I'd lean toward your clutch pack first.

Re: 1985 OMC won't start.....or Tilt

and of course the clutch pack is almost 300.00 i was hoping for a cheap fix i did figure out what motor i had it's the 302FTHRCOM

is the Trim and Tilt motor 2 seperate motors...or is it one in the same? ...it does trim up and doen just can't raise the outdrive.

Re: 1985 OMC won't start.....or Tilt

They are two different motors on mine. One lifts and lowers the entire inboard engine (the trim), and it only moves a couple of inches at that, while the other lifts and lowers the outdrive.

Re: 1985 OMC won't start.....or Tilt

fburke said:

and of course the clutch pack is almost 300.00 i was hoping for a cheap fix

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Good chance you just need to clean out what you have. But I would start at the motor end myself.

fburke said:

...is the Trim and Tilt motor 2 seperate motors...or is it one in the same? ...it does trim up and doen just can't raise the outdrive.

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Two separate motors. Tilt gets your drive up for launching, trailering and recovering ... do NOT run your drive tilted up. It's really hard on the ball gear.

Trim motor (if you have one) is located on the front of the engine at the mount. It raises and lowers the front of the engine to trim the outdrive relative to the keel of the boat - helps you trim for optimal performance of the drive.

Re: 1985 OMC won't start.....or Tilt

The tilt motor engages just the outdrive does not lower even if I push on it. .like it’s stuck…. it’s actually brand new tilt motor… the previous owner replaced it thinking that was it, it's stuck in the up position right now.
I pulled out the pin a previous poster suggested and the pin shaft and worm gear look fine and I didn’t see any corrosion n there.
Maybe I should pull the tilt motor out and make sure it’ the correct motor and was installed correctly…looks like a PITA to get to behind the motor….

Re: 1985 OMC won't start.....or Tilt

fburke said:

The tilt motor engages just the outdrive does not lower even if I push on it.

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If you're hearing it whirring, then chances are you've got a goofed up hammer coupling. Which requires that you:

fburke said:

...Maybe I should pull the tilt motor out and make sure it’ the correct motor and was installed correctly…looks like a PITA to get to behind the motor….

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Pullin' the motor is a booger. On mine, it requires that I pull my rear seats and engine cover off.

... before you do that though: If you unbolt the quadrant gear (big one the drive sits on), can you lift the drive on the trunions? Will it move up and down easily if you've got it unhooked from the gear? If yes, then ...

pull that tilt motor and check the hammer coupling. It's a piece that sits between the tilt motor and the worm gear. Third post down in THIS THREAD has a photo of it. Make sure that piece is in good shape. If it is, try turning the worm gear with a flat blade screwdriver and make sure the tilt gear (small one outside of the clutch pack) is moving. It won't move a lot or fast, but you should be able to get it to turn fairly easily.