Question for the Merc. gurus.

[Ranger 1]

I have an 81 175hp Merc. I found a 1990 200hp Black Max for a great price. It has no controls. Will it be a direct bolt on and compatible with my existing controls. Boat it will be going on is 1986 Ranger 375V. Thanks, Danny.

[nitro_rat]

Your ‘81 should have the single ram mid with the pump in the boat. It has the BIA bolt pattern so the newer motor will bolt right on. The ‘90 should have the 3 ram mid with the pump outside. The trim wiring will be different but the control cables will hook right up. There are two different trim motors for the 3 ram setup (2 wire and 3 wire). Post up what you have once you get that far and we can help you figure it out if you have any trouble!

[Ranger 1]

Thanks Nitro, you are correct I do have the single ram. Is there a way I can check compression on the 200 without controls as it is not on a boat at the moment. The seller says it was running when removed. Asking price is 700 so I figure I could part out and not be to hurt. 500 may buy it. It is a 2.5 right?

[Merc 2.5]

Wanna say 90 is 2.4. 91 was 2.4 and 2.5s

[kingsbiship]

I think the heads read 3 3/8" for 2.4L and 3 1/2 for 2.5L (if they're there)