88 mercury XR4 lower unit

[mbb138]

I Have A 1988 Mercury Xr4 Black Max 150 What Model Lower Unit Do I Have A Bravo 1 , Bravo 2, Alpha Can Anyone Help. Serial# Ob375016 Thank You.

 

[Laddies]

Re: 88 mercury XR4 lower unit

The Alpha or Bravo designations are for stern drive units not outboards.

 

[Faztbullet]

Re: 88 mercury XR4 lower unit

If it is the original gearcase it is the small diameter (4 1/4) style gearcase. The gear ratio is 1:78:1 and is a decent gearcase and uses the 47-89984 impeller

 

[j_martin]

Re: 88 mercury XR4 lower unit

Like he said, it is a little smaller than most V6 lowers. It is a decent LU if it is maintained. I'd run only high perf lube in it.

The smaller size lowers the drag, and increases blowout speed. The XR4 was marketed as a bass bote motor, pushing the edge a bit on HP and performance.

I own one, and I love it.

hope it helps
John