Help me choose a prop!!!

Boat: 1976 Crestliner Crusader 17' 165hp OMC.

18 Pitch - 4 blade aluminum (light)

or

17 pitch - 3 blade stainless steel (heavy)

Use the boat for cruising around and occasionally pull someone on a tube. When there is more than 3 people in the boat it is hard to get on plain quickly unless some people shuffle to the front but its an old boat so no big deal.

What is the main difference with a 4 vs 3 blades and what pitch would be better etc?

Thanks

Re: Help me choose a prop!!!

Hi There,
Love to help.. we need a little more information on your current setup... fill in the information from this link and you're sure to get some great input; from me or several others interested in helping http://forums.iboats.com/showthread.php?t=287818

Good luck!

Re: Help me choose a prop!!!

1) Performance issue you are trying to correct. I just want it to get on plane quicker with more people in boat and go a good speed but I don't need top speed.
2) Current prop manufacturer, model, aluminum or stainless as a minimum. Not sure. 3 blade stainless steal old and heavy
3) Current prop diameter and pitch (required). 14 by 17
4) Wide open throttle RPM and speed with an average load (very helpful) about 3500 - 3600
5) Engine/drive make, model, year, and HP This inboard/outboard runabout has a fiberglass hull, straight 6 OMC 165hp
6) Boat make model, year, length and weight 1976 Crusader C775 17.08 feet 86.5 inches wide. boat weighs approximately 2297 pounds with an empty fuel tank and without any gear or passengers

Re: Help me choose a prop!!!

I think it is the model 14 Sterndrive! The computer recommended an 11, 14 and 16 pitch but I thought higher

Re: Help me choose a prop!!!

Wow, heavy boat for a 17'. You need to pick up around 1000rpm, which would be a different prop pitch of 5" reduction. That is a HUGE drop in pitch.

My guess is the 165HP is NOT giving you 165HP. Has it been tuned up lately? Check compression and timing? Certain you're not water-logged? If all checks out A-okay, go with the 12P, better in a 4-blade for the boat interests you desire.

Good luck!

Re: Help me choose a prop!!!

Sorry! I feel stupid but I was confused. I was confused because I was told that 3 blades have odd number pitches and 4 blades have even number pitches. Well I just got back and realized that my aluminum 3 blade prop is 14 by 18. How can this be? The boat is heavy but it is old, I also realized the other day I had it up to about 4000rpm. So now with this info do I go with a 3 blade stailess 14 by 17 pitch or a 3 blade aluminum 14 by 18 pitch. Sorry for wating your time.

Re: Help me choose a prop!!!

It's never a waste of time when someone is learning something.

Still feel you should confirm your engine is up to snuff. If it is, you still need to add rpm to help your engine; I assume you need to be around 44-4600. that is a reduction in pitch of maybe 3"-4". Go with 4" for a 4-blade for sure. this should set you up if the engine is working properly.

Good luck!

Re: Help me choose a prop!!!

Before changing props or stuff, I would be sure the motor has had a complete tune up recently, good fuel, Carb is in good tune with a rebuild if necessary, Be sure to verify the speed with a GPS and the RPM's the motor is turning.