Reply With QuoteHi about 80 to 90kg will see you pretty close on weight......great engines those although one doesn't see many of them around now...once they where everywhere and pretty much the same motor even through the earlier 80s I think.
Hey Guys,
I'm after a larger outboard. My current motor is a 69 55hp evinrude which I have on my 4m fibreglass savage. I have no idea what either weigh and so I don't know what horsepower would fit the boat? The current motor has a short shaft if that helps. Sorry for the lack of information. I was hoping to fit a 70hp or 90hp depending on what I can pick up
Hi about 80 to 90kg will see you pretty close on weight......great engines those although one doesn't see many of them around now...once they where everywhere and pretty much the same motor even through the earlier 80s I think.
the 55 rude is 88kg, so you need to find out if your hull is hp rated or weight rated
a new 60hp 4st is around 107kg 70hp 4st is120kg 70hp 2st is 105kg 90 2st 123 kg
it all depends on distance you travel because the weight of extra fuel needed over a day can be more than the difference between 2 and four stroke weight
all the 4st benefits and the the advancements in technology all come into play
good luck with the decision
IFISHCQ2
Dont forget that when that old 55hp was new, engines were still rated for hp at the flywheel! So even when new, you were actually only getting maybe 50hp at the prop, best case, more likely about 45hp.
By now, as a 40 plus year old engine, it would be one tired old thing and would be lucky to be giving you 40hp!
i have a mate some years ago who had a Haines 146C. (14ft 6 inches), or 4.42m.
Had a old 50 2 stroke Johnson on it, which blew up one day. Replaced it with a 70 Yammy 2 stroke and at full throttle, it barely touched the water!! Was bordering on overpowered, but was huge fun in experienced hands. Throttle had to be used very carefully.
Your 4m boat is, by comparison, just 13ft long! I cant see any way you would need or want anything near 70hp on the back. Apart from the weight, it would just be over- done by a long shot. A 90hp would, iMO, be plain dangerous.
A new 50hp 2 stroke would probably be a great option, and would not over-capitalize the package.
Note to self: Don't argue with an idiot. They will only bring you down to their level and beat you with experience....
Thanks heaps everyone, I wouldn't of even thought of the current motor running at less then 55hp but that does make sense. I'll definately look at some 50hp motors now. It will be SO nice to have tilt and trim haha
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Yeah I agree with above a large CC 50hp 2 stroke would power it just fine or near equivalent...if for more power and believe it or not a little more fuel efficient once propped well to suit a 70 might easily suit and be a better donk...if the weight does suit..so important.
Any OB can only produce it's hp in response to the position of the throttle so a 12 foot boat with a 350hp even on the back can be driven it's entire life to have no more top speed performance than a 40hp might have...so it's all only and actually all about the weight and nothing but the weight the hull can cope with at rest and low hull speeds as the first consideration.
4 strokes in this (your apples to apples) instance might leave you wanting...unless the more sophisticated reasoning are the ones your interested in.
Good luck
my savage is 4-8 metres, and I have a 70 4 stroke yammi on, that is the max allowed legally
short shaft is going to make life difficult......
I was afraid of this Noelm, They seem to be quite difficult to come by.Originally Posted by Noelm
For the cost of a new motor I'd buy a new (secondhand) boat.
50 HP Yamaha $7K + fitting.
Seafarer V-sea $7K Ready to go & you get to sell the old boat.
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