1988 Mercury Black Max 135 HP Lower Unit fit on 1987 Mercury Black max xr4 150hp?

[mercury23]

1988 Mercury Black Max 135 HP Lower Unit fit on 1987 6v Mercury Black max xr4 150hp?

 

[j_martin]

Re: 1988 Mercury Black Max 135 HP Lower Unit fit on 1987 Mercury Black max xr4 150hp?

If the same driveshaft length, yes. Different prop if the XR4 was original. Original XR4 was 1:1.78 ratio, 4 " prop hub. Standard V6 is 1:1.87 ratio, 4 1/2" prop.

hope it helps
John

 

[mercury23]

Re: 1988 Mercury Black Max 135 HP Lower Unit fit on 1987 Mercury Black max xr4 150hp?

and how it measures my drivesaft ?

 

[j_martin]

Re: 1988 Mercury Black Max 135 HP Lower Unit fit on 1987 Mercury Black max xr4 150hp?

I think if the engines are the same shaft length, it'll work.

 

[mercury23]

Re: 1988 Mercury Black Max 135 HP Lower Unit fit on 1987 Mercury Black max xr4 150hp?

hello again. my 135 hp lower unit does not work.
I am interested in buy a used and good conditions 1987 v6 150hp lower unit mercury XR4

 

[j_martin]

Re: 1988 Mercury Black Max 135 HP Lower Unit fit on 1987 Mercury Black max xr4 150hp?

hello again. my 135 hp lower unit does not work.
I am interested in buy a used and good conditions 1987 v6 150hp lower unit mercury XR4

What didn't work? Any long shaft (20") V6 LU should bolt up, even the old spring loaded ones.

 

[mercury23]

Re: 1988 Mercury Black Max 135 HP Lower Unit fit on 1987 Mercury Black max xr4 150hp?

hello martin, the unit is like mine, damaged gears
that?s why, I want to buy another one, used of course

 

[Faztbullet]

Re: 1988 Mercury Black Max 135 HP Lower Unit fit on 1987 Mercury Black max xr4 150hp?

Go to SEI and get a new one with 3 yr warranty, only $900

 

[mercury23]

Re: 1988 Mercury Black Max 135 HP Lower Unit fit on 1987 Mercury Black max xr4 150hp?

If the same driveshaft length, yes. Different prop if the XR4 was original. Original XR4 was 1:1.78 ratio, 4 " prop hub. Standard V6 is 1:1.87 ratio, 4 1/2" prop.

hope it helps
John

ok well

Hi
if my old case lower unit is 4 " 1.78 , and prop (m turbo 13x4x24)
Below is a picture of my old prop.
what kind of prop I can use for the radio 1.87. for my bass tracker boat 1988 17fl.?

 

[j_martin]

Re: 1988 Mercury Black Max 135 HP Lower Unit fit on 1987 Mercury Black max xr4 150hp?

If it spun up pretty good, 23". If it was marginal low RPM at WOT, 22".

Likely with a bit more drag with the bigger LU, you'll need a 22.