2 stroke to 4 stroke equivalent

 I have a 1990 90 hp v4 2 stroke evinrude on my western craft 525 fibreglass boat.  When i change over to a 4 stroke motor what hp should i be looking at going too.  The same or is 4 stroke power better than 2 stroke so can go lower hp any input would be greatly appreciated thanks.

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 depends how old yours is but

Fri, 2016-06-24 10:06

 depends how old yours is but sometime in the 80's they changed from crankshaft HP to propshaft.

Only you know how it goes now but Id suggest 90-115 if it is inside the HP and weight rating (if it has one)

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pelagicyachts's picture

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90hp = 90hp :-) 4 strokes

Fri, 2016-06-24 11:06

90hp = 90hp :-)

4 strokes are a little heavier than 2 strokes - but I would guess that a modern 4 stroke may be lighter than an old (presuming the Evinrude is old) 2 stroke. If you are happy with the performance with the 90 I would stick to the same hp - 2 strokes seem to have better torque in their power bands but again a new motor will likely perform better than an old 2 stroke
- not an expert just my experience and 2 cents worth :-)
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The new DF90A suzuki weighs

Fri, 2016-06-24 12:14

The new DF90A suzuki weighs 155kg. That would be plenty of power for your boat

 

Jackfrost80's picture

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 I got one in my 5m Seafarer.

Fri, 2016-06-24 14:10

 I got one in my 5m Seafarer. Good holeshot and tops out at 33kn

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Paul H's picture

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I go with the 90 or 115 as

Fri, 2016-06-24 14:06

I go with the 90 or 115 as per Rob

Had a 70 hp 2 stroke on my boat went with a 70 fourstroke - actually have better hole shot (acceleration) now as well as peace, no fumes, less fuel and better top end - I'd be suprised if your acceleration drops with the fourstroke given the 2 stroke is 25 years old.

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Just go the max HP allowed on

Fri, 2016-06-24 14:09

Just go the max HP allowed on the plate

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Being an evinrude and having

Fri, 2016-06-24 17:34

Being an evinrude and having twice as many powerstrokes than a 4st u would need 180hp for equivalent :P.... if your repowering I would consider a suzuki 115 if your boat is rated for it. wouldn't be much difference in price and would still use a shit load less than your current 90... your looking at aprox 15k for a 115 df115a fitted with a digital gage.

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F115 yamaha

Fri, 2016-06-24 21:27

go see Stewart at Jetpower. Had the F115A motor and loved it until I hit something and destroyed it. 

My boats a 6m and repowered with a f150 by the boys there and couldn't fault their service

A lighter 525 with an F115B will do 40 wot or cruise at  25 give or take  givethem a call and see what an installed price is as u might b surprised

 

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115 yMmie 4 banga

Sat, 2016-06-25 10:44

 I had a 5.3m trailcraft with a 115hp 2 stroke on it which I swapped over to a 115 yammie 4 stroke it was right at the top end of weight and HP for that Hull , best thing I ever did the power and economy was unreal. I would always go. Max HP for the hull but that's just me.

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