---

I'm assisting a friend in finding his first Whaler.

We are going to look at a Nauset with a 2012 Yamaha F70 that is available.

I remember reading threads involving this combination but can't find them on an internal search

I recall favorable comments on this model of Yamaha four stroke. Was 2012 the first year of a new version of the F70?

I'd appreciate any comments from people with experience regarding performance of this motor on a 16 ft hull with a load of four people..

My friend's normal use will be 2 people poking around our bay, and I expect this would be fine with 70 HP.

thank you

JimL

---

Hi Jim,
I have a 2011 Yamaha F70 on my 1988 Montauk. I think 2010 may have been the first year for the F70LA, but am not sure. 2012 certainly is the latest version of that motor.

I am quite happy with my combination. 4 adults slows me down to 32-34MPH, depending upon conditions. I am running a 13-1/4" x 13" Stiletto Advantage 4.25 prop. Happy to answer more specific questions if your friend has some.

Dennis

---

Dennis, thanks for the detail on your prop. If my friend buys the boat we'll probably be asking other questions.

JimL

---

Does anybody have fuel economy info for a F70 on an older 17 / Montauk/Nauset?
I'm running a 1998 Yamaha 90 / 2 stroke on my Montauk and probably getting about 3 mpg on average. I'm trying to hold off re powering until the ETec 90 or F90 lose some weight but don't know if I can wait that long.

---

Hi Bob,
On my 1988 Montauk, I get around 7.5 mpg at 21 mph (all statute) with the F70. This was measured with just me (#230) and 23gal of fuel. Fuel consumption measurements were made getting the Yamaha's burn rate from the motor to Lowrance HDS7 over NMEA 2000 cable.

I tried Stiletto 4.25" x 13.25" in both a 15" and a 13" pitch. I stayed with the 13" pitch, and could likely get somewhat better efficiency with a 14" pitch, which Stiletto does not make.

_______15"__________13"
RPM MPH MPG | MPH MPG
-----------------------------
2600 10.7 6.6 | 9.0 6.2
3000 14.9 7.3 | 11.5 6.3
3500 21.0 8.0 | 17.0 7.6
4000 25.8 7.9 | 21.4 7.8
4500 29.1 6.9 | 25.5 7.3
5000 33.1 6.6 | 28.6 6.7
5400 35.0 6.0 | _________WOT for 15"
5500 ---------- | 31.2 5.9
6000 ---------- | 34.0 5.5
6375 ---------- | 35.8 5.6 WOT for 13", rev limited

Nice boat & motor combination.

Dennis

---

Dennis,
That's very impressive, thank you.
I also have the HDS 7 and just bought the NMEA 2000 cable to connect the Sound Dock unit. I didn't think about using it to connect the engine but now that you mention it I need to see if my DSC VHF sports NEMA 2000 too.



Bob

---

I am currently restoring a 1969 16' hull and would love to see an F70 on that hull. I have an F70 on my 1989 Montauk and love it. It is very quiet and starts instantly even when cold (I ran it all through November). It is responsive and fast out of the hole vs. other four strokes. I can't say exacly what it gets mpg, but I can say it sips gas. I have the moeller 24G white topside tank (for Montauks) and I never felt the need to fill it up more than half full most of the time. More days than not I would burn only 5 gallons. At 257lbs the boat is balanced really well. I also moved the battery to the console. At the same time I moved the batt switch, fuel/water separator, priming bulb (and anything else I could) inside the console, which gets them out of the elements and moreover makes the aft cockpit area clean and clear.
I can follow up with prop info, if you would like.
If you search a thread on Whaler Central titled "Speed - Nauset 16 with Yamaha F70" that may give more helpful info.
Happy to help with questions anyway I can.
Dennis - Thank you for sharing all that info - that is very helpful.
Best,
Rufus