New Wheels

Well, not exactly wheels, but a new Yamaha 4 stroke outboard to provide quieter and more reliable propulsion. There was nothing wrong with the old Mercury 650.  It started right up and ran just fine. There was the issue of noise and smoke when backing up. Knowing the motor wouldn't last forever and not wanting to pay full price for new motor, I had been trolling Craigslist for about a year, looking for a Yamaha 70hp four stroke.  Why this engine? Well, this engine is the highest horsepower that weighs in under 300 pounds, in fact, it weighs about 260.  A 60hp Mercury is a bit lighter, but once you move up in power, the weight jumps to well over 300 pounds.  Honda, Suzuki, Evinrude E-TEC all weigh more, so the Yammie 70hp was my target.

At the end of last year I found this. It was located about 2 hours away, but knowing it is rare to find a used one, I jumped on it.  I also don't think it is a 2012, as the manufacture date was 2010.  However, this owner bought it from the dealer as a demo, so it was considered new and had a full warranty.
 

Then came the challenge of removing the old and fitting the new. I had the boat at home for some other work, so I was able to start the process of fitting the new engine. I removed the Mercury and was able to sell in on Craigslist. I had to plug the old bolt holes and clean up the cables, etc.

With my sons help and a chain hoist, I was positioned the engine for bolt holes,

The trickier part was the control handle. I wanted to use the Yamaha control. This required removing the after market control I had mounted in my console.  I could use the existing control cables as they fit right into the Yamaha control and engine.  I had to string the wiring bundle up to the control area.

To remove the old and fit the new, I had to cut away the top of my console to get at the wires, cables and the old unit. Here is the hack job I did to get it out.  I then rigged the cut away piece to fit the new and also mount it higher. This makes it easier to use.  The old unit was pretty low and you had to bend over to give it gas.  With mahogany trim pieces and a round plug, I was able to put it back to a nice looking package.

The Yamaha control includes the ignition switch, which I did not want to use.  I preferred keeping my dash mounted ignition switch, etc. So, I wired around the control wiring.  When everything was hooked up  I test started the engine and found I could not shut it off.  Even though it had no power, the engine just kept running like the Energizer bunny.  I found out I needed to provide a shut-off signal to the engine control unit when I wanted to turn the engine off, something my Mercury did not require.

My ignition switch did not provide this, so I rigged a relay to my switch and mounted it behind the dash.  It provides +12v to the shut-off signal when the ignition key is off, and cuts the signal when the key is in the 'on' position.  

The other problem with the installation was the steering arm. Due to location of the tilt tube or length of the arm, it ran into the wood edging around my motor well on a hard right turn.  I had to cut some space for the arm to move over.

Everything now seemed to working as expected.  It turned out the weekend of Feb. 7, 2015 was warm, so we hauled the boat back to the lake and launched it on Saturday. Everything worked like a charm.  The boat started right up and ran smooth and quiet.  The temperature hit 70 degrees, so we were able to cruise the lake on a beautiful weekend. No more mixing gas, either.

There is one outstanding issue and it was the prop. The boat came with 13pitch prop and I could not go wide open for fear of over-revving the engine. I ordered a 15pitch prop and hope to try it shortly.