Prop question: size & blades

[twerner]

Every time I look up 'prop selection' on the web or this forum I come away with even more questions. At this point, I'm wondering if I can pick up these 2 props without test-driving, checking RPMs, engine temp, etc.

A 3-blade backup prop (which I currently have) and a 4-blade prop to quickly get kids up on skis or wakeboards if I have a full boat. Thinking aluminum or composite because of stainless price.

Boat is '98 Maxum SRL 1900, 18.5' long, Mercruiser (Alpha One) 4-cyl.

Thanks all!
Tom

[mmwjr]

Tom the prop specs would help, diameter and pitch.

Have you tried the merc/quicksilver prop calculator?

I would go with aluminum over composite as it can yield without breaking and can be repaired.

The SS prop does not flex and gives good performance however some flex helps get the boat on plane quicker. Also more chance of drive damage with SS if you strike something.