another estimate of fuel usage.

[achris]

Mercruiser 3 litre engines (and Volvo for that matter) were only even rated at 135 or 140hp... When they first put EFI on them they got 155hp out of them, but the bottom end fell apart, hence the output was never increased beyond 140 on the marketed versions...

Now, if it's a 3.7litre, yes, they came in flavours from 165hp to 190hp... But, an old '470' is NOT what you want... Run Forrest, run....

And the quickest and easiest way to tell the 2 apart is the location of the carb. Stbd side (opposite the exhaust manifold) = 3.7 litre. Carb on top of exhaust manifold (port side) = 3 litre....

 

[viper1]

Actually after checking on The Mercruser's I see they have:GM 4 Cylinder 153 cid (2.5L). , 120 1974-1986., 2.5L NB 1987-1989.140 1974-1986., 3.0L 1987 All with different hp.

 

[thumpar]

Actually after checking on The Mercruser's I see they have:GM 4 Cylinder 153 cid (2.5L). , 120 1974-1986., 2.5L NB 1987-1989.140 1974-1986., 3.0L 1987 All with different hp.

Correct. Some of that has to do with they way they rated them and some to do with performance increases. Either way none was close to 185hp. If was a 3.7l it could be a 185hp and I would run from one of those.