Are parts from 175 black max interchangable with 150?

[mike garrahan]

I have a 1993 175 hp black max. Last week a piston froze or broke apart and the rod and pin went through the side of the block. I talked to a gentleman today who is selling a 150 hp Merc that has a bad lower unit. The powerhead and the rest of the motor are supposed to be in very good condition. My question is will the lower unit from my 175 fit on his 150? How do I figure out which years, models, etc will interchange and are there any special things to look out for? The motor was in good condition with low hrs. but I am hesitant to sink a lot of money into a 20 year old motor. Should I just bite the bullet and buy a new 4 stroke or try and fix the Merc for a reasonable price? Thanks for your help.

 

[j_martin]

Re: Are parts from 175 black max interchangable with 150?

Any V6 LU will fit on any other V6. Some have a pre-load spring on top of the driveshaft, and some pre-load inside the LU. No problem interchanging them. Driveshaft length is the only item that's of concern.

 

[Sprky]

Re: Are parts from 175 black max interchangable with 150?

Depending on what year 150 there may be a gear ratio change. Your 175 has 1.87 gears. The earlier 150's had a 2.1 ratio. If this is the case it will be sluggish coming up on step and may not run quite as fast. But.............it will still get you on the water.

CRay

 

[j_martin]

Re: Are parts from 175 black max interchangable with 150?

Real early 150's maybe. The XR series often had a 4" lower with 1.78 ratio. Still will interchange.

 

[Sprky]

Re: Are parts from 175 black max interchangable with 150?

What year 150 are you looking at?

 

[j_martin]

Re: Are parts from 175 black max interchangable with 150?

They fixed the drive shaft bearing in the second version. There's still a remarkable number of them around. In good adjustment and with the right (HP is recommended) lube, they stand up quite well. I own one. When I got it it had multiple mechanic caused defects in it. Luckily I sensed something was wrong and had it put in proper shape. It had several bearings and seals in it that were obviously damaged by improper installation, and once fixed and adjusted, it runs great.

Now had I run it as I got it, it would have put the pinion out the side in an hour.

 

[Sprky]

Re: Are parts from 175 black max interchangable with 150?

Try a 2.0 unit with a larger prop. You will throw rocks at the 4" lower. Make the torque with the gear instead of the motor.

 

[Faztbullet]

Re: Are parts from 175 black max interchangable with 150?

The 1993 175 is going to be a 2.5 liter and without knowing the year of the 150 it going to be hard to tell you what will interchange other than the lower units. If the 150 is a 2.0 or 2.4 liter there are a number of powerhead/ignition parts that will interchange with your 175.

 

[j_martin]

Re: Are parts from 175 black max interchangable with 150?

Try a 2.0 unit with a larger prop. You will throw rocks at the 4" lower. Make the torque with the gear instead of the motor.

I'm turnin' a 24" high five to 6 grand now. How much more "gear" do you think I need?

 

[Sprky]

Re: Are parts from 175 black max interchangable with 150?

Congrats! You win.

 

[mike garrahan]

Re: Are parts from 175 black max interchangable with 150?

Thanks for the responses. Now I have a better idea of what to look for. If they are both 2.5 ltr. and are the same shaft length then I think I will pick up the other motor and install my lower unit on it and see how it runs. 150 hp should be plenty for how we use the boat. Thanks again for your help.