Tony Brewer contacted me regarding his recent purchase of – Monita a 17’ Mason Marlin which was built by Sutton Mason & Co. Ltd in Mt Roskill, Auckland sometime in the 1950’s. She is powered by a 2003 90hp 4stroke Honda, which Tony feels maybe to heavy. He is considering re-powering with a 2013 Mercury Mariner 50hp ELPTO 2stroke. Tony’s not interested in a high top speed but would like to be able to travel at between 15 to 18 knots. Fuel economy is not an issue as they do not travel far and there would usually be only 2 people on board.
So woodys – the question of the day is – would the boat be under powered with the 50hp motor?
A beautiful boat. I believe the wrap around windscreen Monita has was introduced in 1963. My family had one of the first Marlin 17 built in 1963 and powered by a 75hp V4 Johnson. It was one of the first with this windscreen arrangement. Top speed was 32 mph.
I would not do it, retrograde step in my view.
The Honda weighs ~160kg vs the Mercury’s ~80kg, so the equivalent of one person, no big deal.
The Honda will be easier starting, quieter, smoother and dare I say it more environmentally friendly. Conventional ie non DI 2 strokes, lose about 30% of their fuel/oil mix out the exhaust.
50hp for a boat of this size/weight is pretty marginal
sorry I can’t answer this question, but wonder why he thinks its too heavy. Is it the way it sits in the water, the way it performs, or just the concern of the weight stressing the boat?
My thoughts is that the original big 1950’s engines would be getting up around the Honda weight anyway. Whatever engine that it ran when it was newer would be flywheel horsepower instead of the prop rated horsepower used now, so the 90 Honda would be over 100 Hp in old terms, and the old 40 Hp motor would compare closer to a 30 HP modern engine, so keep this in mind if someone says they had one with a 60 Hp on it, that will be similar to the Merc50.
I suspect guessing what he wants the Merc 50 could go very nicely, as the 2 strokes have good low down punch, and will be significantly lighter, but going to be the whole lot of work changing over and holes etc to drill, selecting prop etc Im not sure I’d be keen to go to all that to fit another old second hand engine.
Let us know why he thinks its too heavy, but if it was me, the Honda with all its curves lends itself best to a colour change and some classic decals added to the cover
70HP – all the way.
I know I’m not answering the question but I reckon “do nothing for the first season”. Then, with the experience gained, make a plan or two.
Might need the extra horsepower just to get her on the plane. I made the decision not to go the extra horsepower with a Morgan we had and ended up having to do nautical gymnastics to get her out of the water
Tony might be better off if he could find one of the 70hp 2stroke merc’s, not much difference in weight to the 50 and much better than the Honda but better grunt than the 50 !