Motor Specs.

[jwr_20]

G'day folks.

I've tried searching some of the threads to find some info about this, but I haven't really had any luck. I am totally new to having an I/O, as I have always had outboards instead. I recently bought a 17' Riviera bowrider, with what I was told has a 140 hp 3.0L Mercruiser. Is there a way I can verify this myself, serial numbers or anything like that? The engine is a 4 cyl. GM block.

Also, I believe the outdrive is an Alpha, it has a waterpump located in the outdrive like my old 75 hp Merc. outboard, and from what I heard, Bravo's have a belt driven raw water pump. What are the differences in the outdrives such as Alpha's and Bravo's, etc?

I guess this is also the time to throw in a question about props. I want to get a 19' prop for that outdrive as well, and the specs stamped on the 17' that's on it now are totally not legible. I want to know about the diameter of the prop, as I was hoping to use my spare prop from my outboard before I sold it, but didn't after noticing the difference in diameter. The outboard had a 13" diameter prop.

Thanks!

 

[WillyBWright]

Re: Motor Specs.

Your 75Hp prop won't work even though it might fit the shaft.

Bravos have a water pump mounted on the motor and shift in the upper half of the drive. Alpha's water pumps are where you say and shift like your 75. They are not interchangable and you won't find packages of 3Ls with Bravos.

3L horsepowers are between 115 and 130. Anytime you want a spec on a Mercury product, the serial is the key number.

 

[Bondo]

Re: Motor Specs.

If your motor is a 3.0l,.....
It'll have a Harmonic Balancer mounted to the front of the Crankshaft......
If it Only has a Pulley,..... It's a 2.5l.........

Merc. Large Outboards,+ All of the common Outdrives have a 4, 1/2" Gearcase,....
Which require the Same Props........
Your Outboard is a Small Gearcase motor with the 4" Gearcase........
Which of course uses the Smaller props.......

For your New Prop,...... Worry about the Pitch,.......
The over all Diameter is determined by the Engineer who Designed it.........
In other words,........
As long as the prop's Hub is the Right 1,....... Just pick your Pitch.........

 

[Don S]

Re: Motor Specs.

Just the year of the boat might help ID the engine.

 

[WillyBWright]

Re: Motor Specs.

I goofed! I believe the older 120s are 2.5L and the 140s are 3L. That would've been back in the 70s and I suppose into the 80s.