Hi, one question for the mercruisers guru...
I am looking at a small powerboat, a Italian Tullio Abbate sea star super in need of some tlc. Motor is good, it's a 7.4 L w/Bravo one
The question is that the seller is saying that it is a 330 Hp motor, but the certificate of the motor says 280...it's from 1989 normally serviced every year....
Who knows what can be the difference ?

the 330 hp motor is a rollor cam motor from 1996-1998 or sp l-29 motor. check the casting numbers on the back top left corner under the left head. Go on www.mortec.com and see what it comes up as.

In 1989 the 7.4 was rated as 330 HP at the crankshaft, approximately 300 HP at the prop through a bravo I drive. Check to see if the 280 is KW rating used in some foreign countries.

The late 80s early 90s 7.4 had cast crank and pistons, most had two bolt main caps and 3/8s rod bolts.

These were good, long lasting low performance engines.

I had twin 330s in my 1989 Baja Sport 280. Engines ran good and had 980 hours on them when I re-powered with high performance 502s.

It's not uncommon for the title to state a different HP than what is really in the boat. One possiblilty is the engine was replaced but I've also seen simple errors on titles. Here in Texas,when the title is first filed a human fills in the blank for HP. They usually copy the info from the MSO but it's easy to make a mistake or misstate the HP. It doesn't really affect the title.