Astro ptp

[DC88]

Let me disclaimer this by saying I know it is a small boat with a small motor but i need a prop to pad starting point.
1996 Astro s-15b
1996 75 merc elpto
6” manual plate
21p aluminum prop

[pmgoffjr]

With an aluminum prop I’d set it at 6” and see what it does.

[ranger168v]

From what I’ve seen and done every bass boat likes em at 3.5 and go up from there

[pmgoffjr]

Well that's true with a V6 engine, current stainless steep prop. He has neither.

[DC88]

I just got a heck of a deal on a stainless 4 blade 19p. Any advice with that prop

[jarhead175]

My suggestion would be do what pat said and report back your performance numbers.

[KandKKustomz]

Well that's true with a V6 engine, current stainless steep prop. He has neither.

exactly hes only dealing with a 75, Pat knows his stuff

[pgs]

Ok I owned a Astro 15 sc quickfire.
A 1990 I repowered with a 96 Mercury 75 carb moter. My 1990 model was the tri hull. I ran mine with a 5 1/2" cmc Jack plate. With the cavitation plate even with the bottom of the boat. The boat ran best. I ran a 25" power tech 3 blade SS prop at 5250 rpm's at about 48 mph.

[DC88]

I ran the boat with the 21p aluminum 3 blade. Ventilation plate 1.5” below bottom of boat.
2 guys, full tank, full livewell and boat did not want to plane out. Rpm on holeshot 3k.

[DC88]

Also im trying to figure out what max rpm is on this little motor. One mechanic told me 5800 others ive heard 5250

[pmgoffjr]

Three cylinder merc is 5250