new f70 on 17ft Mako top speed 12mph!

[diggerman]

Just installed F70 on 17ft mako and the top speed is 12mph and boat fails to plane. ha snew controlbox(new cables set properly) new gas tank ,lines,and seperator/filter. Starts fine, runs well just no speed. Today tried different height adjustment re cavitation plate, no improvement. Followed break in instructions. Please advise, would like to go at least 20mph!! Thanks

[Sequoiha]

At this point i would like to know what prop you have on there and what your rpms are at 12 mph..

[diggerman]

The prop is AL 13 x 19 stock number is 6E5459410000 Thanks for your intrest. do not have rpm's Honestly didn't think I would need tacometer but will purchase and install

[Sequoiha]

19 pitch prop is way to much, i just put a f70 on a 17 key west and put a 13 by 15, rpms are very important for propping a boat.

[grouper sandwich]

I'd look at using a 15 pitch prop MAX with that engine/boat combo. Might even consider a 14 or 13 4 blade. A 19 pitch is WAY too much prop for that set up.

Sequoiha, what kind of top end and hole shot are you getting with that set up?

[Sequoiha]

my hole shot is about 4 seconds to plane, and almost 35 mph with me and my wife on the boat,

[diggerman]

Thanks Sirs for your help, Will advise how I make out!