14'6 Runabout with 30hp Mercury

[tyst67]

My dad and I build the boat in the spring for fishing and drag racing in an open modified class for bragging rights. The boat weighed in at 175 pounds. We put a 30hp Mercury sea pro on the boat. The cavitation plate is 1 1/4 above the bottom of the boat. I am using a stock 17 pitch prop. My last run my top speed was 51 mph. I was bumping me rev limiter. I want to get a better prop for more top speed but I don't know weather to go with a stock 18 pitch a chopper or a cleaver??? I dont know much about the chopper or the cleaver. Can anybody help me with choosing a prop? I want top speed!!!!

[staylor]

..reminds me a bit of my old wood D-Class kneel down marathon boat running a Mk55 40 hp crank rated Merc- but the best I ever got with my $125. well used motor was 45 mph- so I think you're doing great. The pic you show of the hull running at speed shows the motor around neutral trim with the hull runnng just a tiny bit bow high. If you go to a cleaver I believe your running attitude will stay about the same- since cleavers don't have much bow lift- instead they usually end up lifting the stern. IMHO I think you'll be happier with a chopper which will tend to lift the bow a bit. A perfect set up on this type of rig would have the motor cav plate parallel to the water surface and about a 3-5 degree angle between the hull's keel line and the water surface when you're at top speed with optimum balance.
Doug

[David]

Are you turning 7000 rpm or is your speed in kph?
http://www.rbbi.com/folders/prop/propcalc.htm

[JP Love]

My dad and I build the boat in the spring for fishing and drag racing in an open modified class for bragging rights. The boat weighed in at 175 pounds. We put a 30hp Mercury sea pro on the boat. The cavitation plate is 1 1/4 above the bottom of the boat. I am using a stock 17 pitch prop. My last run my top speed was 51 mph. I was bumping me rev limiter. I want to get a better prop for more top speed but I don't know weather to go with a stock 18 pitch a chopper or a cleaver??? I dont know much about the chopper or the cleaver. Can anybody help me with choosing a prop? I want top speed!!!!Go seeyour PM I have a nice prop for you..

[tyst67]

Thanks JPLove!!! Do you have that prop?? I wanted to know how much speed i could get by changing to a chopper or a cleaver??? David it is in MPH!!! Got to my facebook and watch my videos. http://www.facebook.com/#!/video/?id=788685404

[JP Love]

Stil lhave the prop is like new no dings or scratchs.....I do 47 mph GPS on a Princecraft Starfish 16 feets aluminium,really nice prop..

[delawarerick]

Neat boat and that is booking for a 30hp:thumbsup:Rick