Mercrusier 3.0 and 4.3 compatiblity

[Tommy2082]

Hi i have an 87 sea ray seville with a 3.0 mercrusier with a bad outdrive. I have a good outdrive from a 4.3 mercruiser. Mu question is will it work with the 3.0 motor or do i need to find one from a 3.0 thanks in advance.

 

[alldodge]

Yes, so long they are the same type Alpha and MC1

Alpha Gen 2 will not

 

[Tommy2082]

Yes, so long they are the same type Alpha and MC1

Alpha Gen 2 will not

They are both gen 1s will i need to re prop because of the differnce in gear ratios

 

[alldodge]

Being different ratios yes

 

[Scott Danforth]

you can get props low enough if the drive is a 1.81:1. however if its a 1.62:1, no

also, the inline motor has a different input shaft than the V-motors. you will need to swap input shaft

 

[Tommy2082]

you can get props low enough if the drive is a 1.81:1. however if its a 1.62:1, no

also, the inline motor has a different input shaft than the V-motors. you will need to swap input shaft

I do have another question. I know quite a bit about outboards but this is one of my first i\o boats. I can not get the outdrive to go into forward gear. It will only want to go into reverse. When i pulled the outdrive it worked fine. I know you are supposed to install them in forward gear. Is there something that i am doing wrong?

 

[alldodge]

Alpha 1 was from 83 to 90, only the earlier drives have different input shafts

 

[alldodge]

I do have another question. I know quite a bit about outboards but this is one of my first i\o boats. I can not get the outdrive to go into forward gear. It will only want to go into reverse. When i pulled the outdrive it worked fine. I know you are supposed to install them in forward gear. Is there something that i am doing wrong?

Need to turn the shift foot to face straight forward on the drive to align with the other half on the bell housing

 

[Tommy2082]

Need to turn the shift foot to face straight forward on the drive to align with the other half on the bell housing

I have it turned straight but it keeps wanting to go into reverse when i spin the prop.

 

[alldodge]

Rotate prop counter clockwise (reverse) until prop locks. Put bungie on prop to keep it that way, then install

 

[QBhoy]

Engine mounts pattern are different, exhaust cow horns too. Big one is all dependent on gear ratio. Someone will tell you more than I...but I know that most 3.0 will be a 2-1 or 1.8-1. 4.3 will usually be a 1.6-1 or 1.8-1. Then the wild card is high altitude.