18 HPX-V w/ F70 - Enough Power

[HighTailin]

Curious if anyone has powered an 18HPX-V with an F70? If so, was it enough? The spec weights between the 17 & 18 HPX-V’s are similar after backing the engine weights out. My thought… less weight, more hull displacement, possibly same or similar draft as a 17 HPX-V with more room & slightly more deadrise.

[Wahoossi]

Not exact comparison but I had a 17 HPX -V with a Yamaha T 60 higher thrust four stroke and I was not happy with it . Top speed was about 32 -33 mph and cruising was 24-25 at around  4500 rpm’s . I always had HP envy of the guys with the F 90 ‘s . The slight difference in draft wasn’t important to me. I now have a Redfisher 16 with a 115 PRoXS and I can get up to 51 mph in perfect conditions but deal with significant porpoising issues because of engine weight. It is all a trade off .

[Moderator]

They are two different bottoms… The 17 is a technical poling skiff: the hull is designed as a quiet and stable platform for fly fishing and other stealthy approaches for a couple of anglers. The F70 and F90 are the common engine choices depending upon how skinny you need to be.  Speed is not the goal.
The 18 is a fast and stable hull for tournament loads or fishing 2,3, or 4 people. It has a hull that will trim out and cut the chop on open water. With 150 hp they can get ya where you want to fish in a hurry. The sweet spot for all around power on the 18 is the 115 SHO. Great speed and silly economy..  I will say that the F70 will not have enough grunt to suit the average angler.. 

Note: I am not a marketing guy but I have been on both hulls. While the specs may give you that impression, it is all different when you shove a hull through the water with weight in it.. 

Other owners will weigh in I hope.

MM

[geeviam]

On 10/5/2021 at 10:29 PM, HighTailin said:

Curious if anyone has powered an 18HPX-V with an F70? If so, was it enough? The spec weights between the 17 & 18 HPX-V’s are similar after backing the engine weights out. My thought… less weight, more hull displacement, possibly same or similar draft as a 17 HPX-V with more room & slightly more deadrise.

Like Moderator M said, the Yamaha VF115 SHO is a great all around motor for the 18 HPX-V.  If you're looking for the least amount of weight on the stern, the Suzuki DF90A is the lightest 4-stroke 90 available, and would be the smallest motor I would install on that model hull.  IMO, the F70 doesn't have enough muscle for carrying a load or hole-shot.  I have a Suzuki DF90A and the torque of the 2.59:1 gear ratio rockets the skiff up on plane, and the fuel economy is awesome, because it can turn a larger pitch prop.  Just my two cents 😊

[hawg]

I'm running a 17 HPXV with a Yamaha F70. With 2 people on board, the performance is adequate at best. Top speed is less than 35 MPH. Fuel economy suffers greatly (drops from 7.5 MPG to 5.2 MPG) when running above 26 MPH. Do yourself a favor and get the bigger motor. ("There are few problems in life that cannot be solved by a bigger hammer or more horsepower" Anon.)

[fin-addict]

70 is just to small, won’t be happy with it. JMO 

[conocean]

I haven’t heard of anyone daring enough to put an F70 on an 18HPX. Mine was built with an F90 & 35 gallon tank. I still love it but I wouldn’t want less hp or a smaller tank. The only time I wish I had more hp is when I fish with two larger dudes @full load which happens rarely. I sip gas while cruising around 32mph @4400 rpm with normal load & draft is 8-9” depending on how full the tank is.