Prop wont go any faster.
#1
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Prop wont go any faster.
I have an 18ft Formula. I built a 355. No matter what prop I put on it, it wont go any faster than 54mph. I tried it back to back. 21 aluminum, 23 aluminum, 21 Mirage plus, and a 23 Mirage. Both of the stainless props are in perfect condition. The motor will rev faster but no speed is ever gained past 54 on gps. It feels like i am doing a burnout. Could a crooked and rough skeg cause this?
#2
What is the condition of the bottom of the boat? Any bottom paint, growth, or other? It sounds like you have something robbing hydrodynamics; which could be the skeg. Does it track straight? Have you run a prop slip calculator with the different props and RPMs? Have you tried a 4 blade? Are you sure the engine coupler is in good shape?
#4
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So an alpha SS would probably work wonders for me then? Are there any band aid fixes for a drive thats too deep? And why would Formula mount a drive so far down?
#7
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It has an old school Mallory Mercruiser points setup with a points eliminator kit. I have also checked my advance curve and it is within spec. I can rev to 6k but get no gain in speed.
Last edited by 79formula; 07-26-2013 at 10:20 PM. Reason: Advance added
#9
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Ill be bummed if I rebuilt the transom, rebuilt the drive, built a 400hp motor, all to gain 0 mph. I really wanted to go for 60s, if the drive is too low it will be where my quest for speed ends til I can buy a 242.
#10
I have an 18ft Formula. I built a 355. No matter what prop I put on it, it wont go any faster than 54mph. I tried it back to back. 21 aluminum, 23 aluminum, 21 Mirage plus, and a 23 Mirage. Both of the stainless props are in perfect condition. The motor will rev faster but no speed is ever gained past 54 on gps. It feels like i am doing a burnout. Could a crooked and rough skeg cause this?