Yamaha 60hp conversion to 70hp

[jasonlem]

!@#

[Hot Runr Guy]

I'm pretty sure this won't be as simple as removing a restrictor and re-flashing the ECU. One of the major differences is in the induction system, the F70 has 4 valves per cylinder, the F60 only 2.

Take it from someone who made the same mistake as you (going with a 60 4S), a 75 will put a much bigger smile on your face,,,,,

HRG

[GP-NJ]

X2 Hot Runr Guy's comments. BTW, Yam performance reports indicate only a max 2 mph gain going from a 60 hp to 70 hp. If your hull is rated for a 75 hp, then coulda, woulda, shoulda will always be your nemesis until you decide to forget about it and just enjoy your rig, upgrade the outboard or just go ahead and trade what you currently have for a new rig. One thing is certain - If your buddies know that your underpowered rig really bothers you, they will always remind you of that fact. I would just enjoy the rig and promise myself to never make the same mistake again. I always max the power.

[jrdonicht]

Two entirely different motors. 60 verses 70 Even the cylinder head is different. The 60 is the mate to the 50. With the 50 having the restrictor plate and different ecu which cannot be re flashed. The 70 does not even run the same spark plugs. Different pistons. The 70 is in a category all by itself

[jeffbilodeau]

Wow!!!

[jrdonicht]

Dont believe me believe Yamaha http://www.yamahaoutboards.com/outbo...specifications Read and you will see the difference. Like Hot runr guy said for starters. 16 valves verses 8 valves



Yamaha News | Posted On: 04-07-2010
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Breakthrough technology delivers lighter, more economical 4-strokes.

Genuinely ‘big’ or ‘important’ events in outboard development don’t happen that often. In fact, the most recent was probably Yamaha’s introduction of its ground breaking fully 4-stroke line-up
For the new F70A, Yamaha engineers have designed a unique four-valve-per-cylinder configuration in which the valves are actuated by a single camshaft instead
of the more typical twin-camshaft arrangement. This highly unusual design not only allows greater intake and exhaust valve area – which contributes to volumetric
efficiency – but also reduces the weight and parasitic friction losses that are the inevitable penalty of using twin camshafts.

[Chad V]

If you want to see what parts are different go to the Care & Maintenance drop down on the Yamaha site and pick Parts Lookup. Do a split screen, one for the 60 & one for the 70. Pick CYLINDER CRANKCASE 2 & VALVE from the Step 4 drop down. You will see people here do know what they are talking about.

[Johnnielund]

I made that mistake as HRG. I bought a 60 E-TEC and after the first season I traded it on a 75 E-TEC.
Jim