my new to me boat hates me.. help with engine coupler and alpha one

c91x

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Joined
May 26, 2008
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16
1981 3.0 merc with alpha one outdrive

a couple of day ago the boat left me stranded. i changed out a bunch of things drained the old gas and put new gas in it. Went to start it and it started but was running crazy rough and you could see the stringers flexin from the motor rockin so much. it died. i took off the fuel line and ran the rest of the gas out of the lines.. started it up and it ran good but i notice water coming in under the engine and realize i'm not pumping any water into the impeller and none is coming out the exhaust. Why isn't the impeller picking up any water. hoping for the best i put it in forward and check the prop. It locks in place but i put some pressure on it and it spin with resistance but it is definetly not turning the motor over. so i check the oil in teh outdrive. it's good no metal . i check the ring and pinion its good. pull the whole upper and lower unit off and see on the drive shaft the splines have some spurs on them. I'm new to Inboard outboars so i check out what comes next in the manual and see the coupler shredded. So i check the stringers again(checked them when i bought it) to see if they were rotten and they're solid so i guess just the flex from the motor rocking so bad caused it to eat it self so i need a new upper driveshaft and coupler.

now here's where i need help. i have no idea what coupler to get what driveshaft to get and where to get a new gasket for the outdrive to bellhousing and o rings for the water jacket?

do i have a one piece or two piece main seal? 3" or 3 1/2" coupler

alpha one gen 2 or gen 1?

if anybody knows a one stop spot or kit where i can order everything i'd really appreciate it
 

c91x

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May 26, 2008
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Re: my new to me boat hates me.. help with engine coupler and alpha one

also should i replace the bellows while i'm at it. they look fine and everything but your know while i've got it torn down it's be alot easier
 

Bondo

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Re: my new to me boat hates me.. help with engine coupler and alpha one

Ayuh,....

You have the 2 pc. rear main seal,+ probably a Pre-alpha drive, either the "R" or the "MR" drive...
if anybody knows a one stop spot or kit where i can order everything i'd really appreciate it

I think iboats has all the stuff you need...
 

c91x

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May 26, 2008
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Re: my new to me boat hates me.. help with engine coupler and alpha one

thanks i guess i just figured it was an alpha becuase the manual is for alpha one outdrive
 

Don S

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Re: my new to me boat hates me.. help with engine coupler and alpha one

alpha one gen 2 or gen 1?

Neither, you have a 1-Drive, coverd in OEM service manual #4 (you can find it in the Adults Only sticky at the top of this forum)

The OEM coupler is PN 76850A2 which is Sierra 18-2171
 

c91x

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Joined
May 26, 2008
Messages
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Re: my new to me boat hates me.. help with engine coupler and alpha one

one more question. what's the easiest way to get the coupler off? can i just undo the rear motor mounts and loosen the front take off all the linkage and exhuast manifold and swing it to the side?
 
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