Motor coupling 2.5L

[KIRKUSN]

I have a 1983 mercruiser 2.5l 120 hp alpha1 out drive and the coupling on the motor spun today and i dont know what coupling to replace it with i want to have the replacement in hand when i lift the motor out to do a quick change. ive found 3 couplings i can replace it with ive found one for a late model, early model, and "MR" stamped one heres a link thank for the help

http://www.go2marine.com/productcenters/sierra/sierra/8024_PDF1_V_665.pdf

 

[achris]

Re: Motor coupling 2.5L

Unfortunately, in this case you don't know which one you have until you pull the engine and have a look. If I was a betting man (and I'm not) I'd plumb for the 'early model' (18-2171).

Chris..........

 

[TFHTECH]

Re: Motor coupling 2.5L

the diferance would be the dia. of the fly wheel 12.5 or 14 inch and you should replace the input yoke at the same time but first you need to find out what made it go bad most time its the sringers are rotted out the cut off year was 85 thats wy it hard to tell what you have untill you get it out

 

[mkast]

Re: Motor coupling 2.5L

What is the serial number on the engine?

 

[bigskiohio]

Re: Motor coupling 2.5L

why replace input yoke? easy fix takes less then 8hrs,need alignment bar . motor should come out fast thee unbolting of coupler is a little work as there is no room for socket.

 

[Don S]

Re: Motor coupling 2.5L

why replace input yoke?

It depends on how the coupler failed. if the splines spun out of the coupler, the splines are probably worn down on the shaft as well. Which would cause the splines in the new coupler to fail quicker.
If the coupler fails by spinning the rubber as yours did, then there is a good chance the shaft is fine. But they should be checked.

To the original poster, as Chris said, the 2171 coupler is probably the one you want since the triangular one was for models from 85 and newer. but without a serial number that is only an educated guess.

 

[KIRKUSN]

Re: Motor coupling 2.5L

i replace the bellows and water pump and bearing 6-mo ago when i bought the boat the alignment was fine. I check the stringers and there solid, when i originally bought the boat salt water was running down the shaft into the coupling where the motor was and i think thats why the coupler on the motor went bad. the shaft is still in good shape there is nothing wrong with it.
the serial # for the motor is 6290495 and the drive is 629323. By the looks of it that i can see i dont think that it has the triangle mounting bracket on it it looks like its probly gonna be mounted straight to the flywheel.

 

[Fishermark]

Re: Motor coupling 2.5L

i replace the bellows and water pump and bearing 6-mo ago when i bought the boat the alignment was fine.

....when i originally bought the boat salt water was running down the shaft into the coupling where the motor was

Did you replace your u-joints while you were replacing the bellows, etc? If not, the chances are good they need to be replaced as well.