196 GEARBOX REDUCTION 1.5:1 v 1.23:1

[SNEKLIFTER]

Hi to everyone out there.
I have recently purchased a 2002 196 fitted with a PCM excalibur 330hp, connected to a 1.5:1 reduction gearbox, and running on LPG.
If anyone can help please. My questions are.
1, Is the 1.5:1 the standard gearbox reduction, or is it the 1.23:1?
2, What in practical terms are the difference between the two?
3, Also that prop would be the best choice for this engine/gearbox combination? The prop that is on now is stainless steel. I do not know dia, pitch, or make.
Thanks in advance for any help.
Guy.

[DanielC]

The 1 to 1.23 is the standard transmission ratio. It uses a 16 inch pitch propeller.
The 1 to 1.5 I think was used with a Mastercraft prostar, with a "power slot" transmission.

Theoretically, a higher pitched propeller, turning slower is more efficient.

What RPM does the engine run at WOT? I think it should run around 5K RPM, but I could be wrong.

On some propellers, the diameter and pitch are stamped on the hub, and the numbers are under the propeller nut, or they could be on the strut end of the propeller hub. Another option is to take, or ship the propeller to a propeller shop and have them determine the pitch.

[SNEKLIFTER]

Thanks Daniel for your help.
Unfortunatly I can't check the boat myself right know, as I took it to the Nautique dealership, www.midlandsnautique.co.uk 120 mile away at the weekend for winter storage. Have phoned them today, and they think I am mistaken and the reduction is 1.23:1 They are going to check it out, and let me know on Friday.
We tell you what they say.
regards,
Guy.