1981 Mercury V225 on a 20 Master Angler

Bigshrimpin · #1 07-25-2005, 04:03 AM

finally got the bugs worked out of my 1981 Mercury V225 blackmax. Today I ran the boat 20 miles down river.

Top speed is 43/44 mph @ 5800 rpm (with a 17pitch dinged aluminum prop). I'm looking to swap to a 19 or 20 pitch prop . . . Fr. Frank, Brad or any of you other guys with these 2.4L blackmax motors - what prop do you recommend?

PressureDrop · #2 07-25-2005, 10:10 AM

im sure im not gonna be the only one to say that those numbers sounds kinda slow for a 225. sounds like its tired becuase you should be seeing closer to high 50's

Ben

NAHIM · #3 07-25-2005, 06:34 PM

I have a 20ft SC with a 96' Mercury 200hp 2.5 and it tops out at 50mph with a 17 pitch at 5900rpm (trimed). When I ran the 19pitch Mirage I reached 53mph. at 5500rpm (trimed). He works better in low and mid range with the 17 Mirage.5800rpm's is were you need to be

"Tight Lines"

Bigshrimpin · #4 07-25-2005, 07:29 PM

Ben - You're probably right. The motor is 24 years old, but still has 120 - 122 psi in all 6 cylinders. I think the prop that I'm using is a big factor. It's a little dinged. The v225 was re-rated to v200 in 1983 when merc chaged over from rating HP at prop instead of the powerhead.

R. Nahim - What diameter 17 pitch mirage do you run?
I believe those mirage props are progressive pitch props (also heavily cupped).

The best part about the engine is 3mpg @ 3800 rpm => 31/32mph cruise (per Navman)

jorgeinmiami · #5 07-25-2005, 07:39 PM

glad to see some info on what mine will do.
I just got mine ready and will be splashing this weekend.
I also have a 20 cc with a 98 merc 200efi.

NAHIM · #6 07-26-2005, 12:15 PM

Bigshrimpin,

Diameter on the Mirage is 15 1/2. A Lazer 14 x19 s/s prop would be the fastest for a 20 ft SC. I have a 20SC with a B-bracket and trim tabs. I wonder how the ride and performace compares to a transom mounted engine.

NAHIM · #7 07-26-2005, 05:21 PM

Jorge,

Were will you splash you're boat. Are you in South Miami. I'm curious on you're speed. If you are close to my neighborhood I'd like to show you my boat.and share ideas

Fr. Frank · #8 08-03-2005, 10:02 PM

Bigshrimpin, I would stay with the 17" pitch, but definitely go to a Mirage, or a PowerTech 4-blade such as the UN200OFS4R17P. They're about $650 or so. If you want, PowerTech will even make you a custom prop if you give them your loaded hull weight and motor, and tell them you have a variable dead-rise SeaCraft hull. That's what I did, and only paid $770. I have a 15"x16 1/2"P UN200 series 3 blade.
The stock UN200 Offshore 4-blade right 17 Pitch should work fine. It has a 15 1/2" Pitch
On the other hand, I saw a 17"P Mirage on Ebay for $150.

NoBones · #9 08-03-2005, 10:57 PM

My SF 20 has a 97 200HP "Carbed" Merc which has been tricked out by my marine mechanic, Slingin 21" Laser II
prop. By myself at 5800rpm on the GPS tops out at 63mph.
My 84 225 Merc was around 50mph. Horse power today is rated
at the prop not the flywheel like the old motors.

jorgeinmiami · #10 08-06-2005, 10:06 AM

Hello,

I would like to get together and compare "notes" on our boats.
I was recently on a little R & R in the keys and the boat ran great.

Call me 786-287-5370

Jorge