1992 Astro S-18FS Prop Suggestions

[Starquesttsi]

Hello all! Let me thank you in advance for any advice you can give. I recently picked up a really nice 1992 Astro S-18FS with a 150 Black Max(Serial 0D177410). The powerhead was blown so I replaced it with an 1986 150hp XR2 powerhead(serial A933933) and changed the exhaust tuner to the 200hp bell style tuner. So it's basically a XR2 with the 2.00 ratio lower unit. I also installed a 5 1/2 inch TH manual jackplate. It currently has a 21P Laser II prop, 5" below pad, and does 54mph at 6050 RPMs. From the reading I've been doing it seems like the 23P tempest 3.5" below pad is the magic combination for these boats. I'm after top speed so given the numbers I'm getting should I get the tempest 23P or something else?

[Procraft180Pro]

Nice boat! A Tempest Plus is definitely the prop you want to try! I'd go with a 24P to start with. I have one on my 93 Procraft 180Pro/93 Merc XRi 150 and I'm getting 60mph at 5300rpm with two 170lb people and a tournament load. I have a 5" manual jackplate set at 1" below full lift as the Tempest props are "surfacing" props.
I'm currently looking for a 23P Tempest Plus to bring my rpm up a bit, but I'm still getting 65mph @5600rpm by myself with a light fuel load.

[Starquesttsi]

Nice boat! A Tempest Plus is definitely the prop you want to try! I'd go with a 24P to start with. I have one on my 93 Procraft 180Pro/93 Merc XRi 150 and I'm getting 60mph at 5300rpm with two 170lb people and a tournament load. I have a 5" manual jackplate set at 1" below full lift as the Tempest props are "surfacing" props.
I'm currently looking for a 23P Tempest Plus to bring my rpm up a bit, but I'm still getting 65mph @5600rpm by myself with a light fuel load.

Wow, those are pretty good numbers you're getting there! My goal is 60mph so it's great to hear this is possible with your setup being pretty similar to mine. Thanks for the suggestion, I'll start looking for a prop.