Looking to get more speed on new boat

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mbourgeois13

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Hello everyone, im new to the site but im looking for anyone that can help me get anymore speed from my current setup.

Current setup is:
2004 Southfork 15x52 v front
1999 Yamaha 60 hp
Power Tech SS prop 13" 15 pitch
Step-N-Trim tabs
Unknown brand hydrofoil
RPM at WOT 4100 on tiny tac

Top speed 30 mph on gps with two aldults
 
Get rid of hydro foil - if you have tabs you do not need both anyway. Just drag in the water

Bet you gain 3-6 mph just by doing that
 
what condition is the motor in? is the compression good? ... how heavy is your rig? pics?
 
Not sure about weight. ive tried running just tabs without foil and foil without tabs and boat performs better with both on. Motor is in good condition and has good compression. Im working on getting pics up
 

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Just got back from taking my girlfriend out for a ride with both of us sitting in rear seats top speed was 30 mph with a tiny tac reading of 2410 steady at full throttle. Still dont have any idea how much boat weighs.
 
After full description of boat and power:

1 - Get your engine manual
2 - Compression each cylinder
3 - RPM at WOT normal load
4 - Prop diameter x pitch
5 - Re-CHECK RPM - sounds like it's not wired or programed properly

5 - redux - because I don't think you'd do 30mph @ 2400 RPM - ever with that prop - or even get on plane @ 2400
 
Does not sound like you're getting reliable info from the tach - you need that working first before you start playing around with anything else.
 
Overpropped.

You're going to be looking at a 13" pitch to get you in the ballpark, maybe even a 12 but I'd start with 13".

People keep thinking that the 15"+ is "right" for those "bigger" motors but they fail to realize that the lower unit gear ratio is pretty sorry, at I think 1.82. The 70hp motor had a 2.33 and would turn a 15"+, but it was a different foot altogether (similar to the 85 and 90 hp).

Your hull is on the heavy side and is not a speed demon. They ride good but they tend to have a lot of drag.

Start with the prop and go from there. You're going to want to see 5500-5700 RPM max with a light load. Don't be scared to go a hundred or two over the max recommendation. Then when you get it loaded down with the kids, wife, gear, etc...it'll be pretty close to optimal.

I wouldn't be surprised to see it pick up speed with a smaller pitch. Sounds backwards but a lot of times it works out that way.
 

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