Hi guys, went out on the water again and can now definitely say:
MacM + 1950cc = HUGE success
We had a few days of really bad weather with rain and wind blowing up to force 9, so we were restricted to port (and to home). Now the sun is back again and winds have dropped down to force 5. So I grabbed the opportunity and went out on our MacM again to log break-in hours.
I am now past the point where I can go above 4000 rpm and only briefly touch WOT. I am the type of guy that likes to be on the plus side of engine break-in hours and give the outboard a more than adequate time to smoothly break-in. So, I am not in a hurry to go flat out but at the same time have all the curiosity in the world to see how the new engine will perform with the MacM.
Now that I have touched on WOT I can definitely say the
MacM + 1950cc is a HUGE success (Victor, this is your line

).
It seems that the 3x14x17 prop may be just right; perhaps a little light now that the boat is on the light side but will wait till I have all my equipment back on board (summer cruising mode) to objectively evaluate the prop's performance. I am not sure if later on I shall need to try out an appropriate four blade; we shall see.
In any case, yesterday I went out with a hefty friend so I had 100 extra kilos on board (that is equivalent to the Admiral plus daughter plus some carry on belongings) and I tell you, Suzi did not in the least feel the difference; no sweat!
Once again a weather shore, so we had some wind but no significant waves - going against the wind (0 degrees) versus going dead downwind I had a difference in speed of approx. 1 knot - upwind engine trim all the way down worked best, downwind, a touch of trim up was required. We had a small handheld GPS with us and took some readings, but did not again take careful exact measurements nor record them on paper (this will come later) but I can tell you that in the high end rpm range we hit 20 knots with ease!!! (1 knot = 1 nautical mile per hour - not to be confused with the statute mile) (20 knots= approx. 23 miles per hour). And there is room for more - Suzi has a LOT of power.
As Road Soldier would say, I "chickened out" when I hit 5.500 rpm (with ease) for a second or two and throttled back.
Highlander, the deep roar of the motor, like your Merc, is a melody to my ears. Very sweet!!!
However, I am experiencing an echo effect in a certain rpm range when the motor is trimmed all the way down (touching the stern). The working vibration of the motor echoes through the boat like a speaker. Here I am with an engine that has acceptable decibel levels and I am annoyed by the echo effect. Maybe when mattresses and all my stuff goes back into the boat, it will help dampen the sound. Has anyone else with the bigger engines experienced this?
Beene, as my M was sliding on the water, it felt just like your video on ‘glass’ (and I had far from perfect conditions). Really cool!
Once again all trials without ballast.
As for fuel consumption, it is hard to gauge when you are starting and stopping all the time and continuously varying your engine revs but by following the rate at which my 25 litre tank emptied, I can say things look pretty promising. When I make one of my regular trips to one of the nearby islands I shall be able to make an objective evaluation by comparing what I used to burn with my previous 70. That will come soon.
I am now convinced that increasing engine volume is the way to go with the MacM!!!
That’s it for now, hope you find my report enlightening.
Happy sailing
Octaman
