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1980 omc 80 hp 800 NO REVERSE

1

19beachcraft

New member
I have a 1980 omc 800 I think is what they call hydrostatic assist. I have very little reverse when it's in the water, motor rev's like it should but boat barely moves. When I take it out of the water shut the motor off and put the throttle in forward and try to turn the prop by hand I can't turn it the in either direction. When I put the throttle in reverse I can turn the prop clockwise with some resistence but can't turn it counterclockwise.
Can somebody out their tell me how to fix the reverse without it costing me a lot of money that I don't have.:confused::confused::confused:
 
Re: 1980 omc 800 NO REVERSE

Get a manual.

When was the last time you changed out the water pump ?

The way i see it it's ether the water pump shafts splines went or the coupler.

Want a post i made about how to change out the pump just ask.
 
Re: 1980 omc 800 NO REVERSE

19beachcraft said:
I have a 1980 omc 800 I think is what they call hydrostatic assist. I have very little reverse when it's in the water, motor rev's like it should but boat barely moves. When I take it out of the water shut the motor off and put the throttle in forward and try to turn the prop by hand I can't turn it the in either direction. When I put the throttle in reverse I can turn the prop clockwise with some resistence but can't turn it counterclockwise.
Can somebody out their tell me how to fix the reverse without it costing me a lot of money that I don't have.:confused::confused::confused:
Click to expand...

That's one of the reasons that Stringers were replaced with Cobra drives. If you want on the water, you'll pay to get there.
 
Re: 1980 omc 800 NO REVERSE

check the lower unit oil. If it is milky/watery the hydro assist plunger may have rusted inside. Some visual checks of cable movement in the converter housing and visual inspection of the shift cable casing and routing would be a good start.
 
Re: 1980 omc 800 NO REVERSE

pull the water pump all the upper oil got to come out. That motor got to be running to shift with a hydro-mechanical drive.
 
Re: 1980 omc 800 NO REVERSE

I think your right, I need to get a manual and start studying.
I don't under stand why the water pump would take out my reverse.
 
Re: 1980 omc 800 NO REVERSE

I checked the oil, someone told me that if I drained the oil and filled it back up with automatic transmission fluid that it may free up the plunger and it may start shifting better.
What do you think.
 
Re: 1980 omc 800 NO REVERSE

I hooked up water to the boat today and put it in reverse and the prop turns but when I put some resistance on the prop it will stop, when I take the resistance away it makes a chattering noise and starts spinning again.
I think I may have some gears out.
 
Re: 1980 omc 800 NO REVERSE

when you pull the water pump the shafts come out with it and one gear the other gear will be visible.

Here is how to remove the lower to get to the water pump in the upper.

No need to remove the entire drive.

Have a table or a large cooler or chair ready on the port side.

On a trailer lower the bow as far as it will go, and raise the drive 1/2 the way up.

Remove the very top bolts, and the exhaust and the lower will come down. place it on the table and tie it to the swim platform. be careful of the cable don't pull on it plenty of play in the cable.

remove the 4 bolts facing u in the upper drive from the bottom and the whole waterpump and shaft will come out. you could raise the drive a little more to make it easy, i sit on a milk crate when i pull the pump.

My method does not require removing the cable.

Keep us posted ! I have a feeling this ain't over.
 
Re: 1980 omc 800 NO REVERSE

19beachcraft said:
I hooked up water to the boat today and put it in reverse and the prop turns but when I put some resistance on the prop it will stop, when I take the resistance away it makes a chattering noise and starts spinning again.
I think I may have some gears out.
Click to expand...
doubtful... one of the two gears involved in reverse is also involved in forward

that sounds dangerous...you must be using a 2x4 or something....don't do that

19beachcraft said:
I checked the oil, someone told me that if I drained the oil and filled it back up with automatic transmission fluid that it may free up the plunger and it may start shifting better.
What do you think.
Click to expand...
not going to hurt anything. don't go boating with atf in there though.

I don't fully understand the water pump thing either...if forward works in the lake under load, the vertical shaft is ok.
 
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