went out for first speed run. Prop suggestions please
 

Finally took the boat out for a good run. It's a little 20ft Baja islander 204. I changed the 4.3 out for a mild 350 I built up. Waiting for the 1.8 alpha to explode, but I don't have the $ for a 1.5 drive.

I tried out a mirage plus 23 and it felt pretty good, but too many rpm's. Was going 57 on gps at 6000 and still had more throttle left. Anyone know a good prop to change to that won't kill the holeshot completely? Plus with the 1.8 I don't want to grenade the drive with too large of a prop. I'll probably stick with what is here, but curious non the less if something could be a little better

Before this prop I ran the 23 aluminum prop. Couldn't get more that 1/2 throttle without overreving the motor, It sounded like the prop would break loose when the secondaries opened.

Try merc bravo 4 blade 26 pitch. It might work well with your top end and handling. Hole shot will be good. No wot to get on plane or explosion!!!!

heard somewhere you shouldn't use those on alphas. Is that rumor or not?

If you want a 4 blade, I hear the Merc Offshore prop works good with the Alpha.

steve/AUSTIN
 

your in AUSTIN,There are several dealers there that have props you could try.

try a 24,26 pitch bravo-one

then try revoultion four blade prop in a 23,and a25 pitch also if you can? try some higher pitch 3 blds.

good luck,Darin

Try http://www.fullthrottlemarine.com/

Talk to Bob (bobl on OSO), he is very knowledgeable.

HWY 71 Spicewood, TX 78669
(830) 693-5591
(830) 693-7472 (fax)
[email protected]

I have a quicksilver 25" pitch i will sell cheap.(three blade)

that will give me enough additional $$$ to have Darin at Houstin lab my other props. :D a win..win....

sorry if i am stating what you may already know, but
for top speed, you want it propped to run WOT at your peak power when lightly loaded. so depending on your cam, I would think you want lower R's like in the lower 5's and for reliability, it seems much over 5300 is not good in the long term.
a boat motor cannot survive at the R's you think of running a pass down the drag strip or even circle track racing.


let me know if interested in the prop.

Ramb

27p mirage 3 blade. I wouldn't run an alpha over 5000 rpm or thereabouts.

BT :cool:

steve,don't even try to prop it,i did the same thing years ago,baja 184ss,350 crate motor,crane 272 cam,intake and 750 carb.i changed the gears to 1.50 ratio,put a 26 pitch turbo on it,the thing would run 75 mph all day long @5200 rpm's.boy was that a fun boat,18 gallon gas tank 25$ would fill the tank with super and have a blast.now it's a 102 gallons and you can watch the gas gage move when touch the throttle.

IVE GOT A 25 MIRAGE NOT A PLUS BUT WAS A FAST PROP YOU CAN HAVE FOR $150 SHOULD BRING YOUR RPM DOWN TO 5600-5700 IN MY OPINION A 4 BLADE WILL PUT TO MUCH STRESS ON THE ALPHA.ANY QUESTIONS ON ALPHAS CALL MARTY AT MOSS MARINE IN AMITYVILLE LONG ISLAND.THEY RUN A SMALL GLASTRON WITH A JET MOTOR AND USE AN ALPHA DRIVE.HE TOLD ME IT WILL LIVE LONGER AT HIGHER RPM AND LESS LOAD THE LOWER RPM AND LOADDED TO THE B-LLS.YOU KNOW YOUR ON BORROWED TIME WITH THAT DRIVE GOOD LUCK