What 6 cylinder Mercury is this?

[Comoxsam]

Hello all,

I'm going to check out a 1975 Starcraft Chieftain for possible purchase this weekend. The owner only knows the engine is a "6 cylinder Mercury and the leg was rebuilt a few years ago."

I've always been an outboard guy so I have limited knowledge about which models to watch out for etc. I'm hoping some experts here can help me identify what engine this is so I can do a little research.

Thanking you in advance.

 

[jimmbo]

About 160 - 165 hp
Based on the 250 cubic inch chevy
WOT Range 3900 - 4300 rpm
1.68:1 gearing

 

[Scott Danforth]

it does have a heat exchanger.

 

[Comoxsam]

Thanks guys! Are these considered a good engine or should I be cautious?

 

[Scott06]

Thanks guys! Are these considered a good engine or should I be cautious?

Engine is very mechanically reliable if reasonably taken car off. The mc1 outdrive is also good. The issue may face due to age is some parts being no longer available as both the engine and outdrive have been out of production for like 40 years….

You can bolt on a new R/MR/Alpha one gen one outdrive if need be.

 

[Scott Danforth]

Thanks guys! Are these considered a good engine or should I be cautious?

That motor and drive are 50 years old

If the heat exchanger maintenance has been kept up, then it may last another 50.

However that chunk of iron is heavy

A 4.3/A1G2 combo can be dropped in saving 200# and adding 50-60hp

 

[Comoxsam]

Thank you!