What size engine


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New member
Feb 20, 2023
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Nova Scotia
Could someone help with some advise on what size outboard would probably the best.
I have just purchased my first 12 aluminium v hull boat an older Princecraft Springbock.
I was thinking along the lines of 2.5hp/3.5hp or 4hp Mercury/ Tohatsu.
Is the extra money for the 4hp with it's reverse gear and extra hp be worth it, and would the 1.5/0.5hp be noticeable.
Not sure, but more HP is typically better than not. Also buy the Tohatsu if a Dealer is near you, as they make all the small outboards for Mercury.

Or check the schematics online at marineengine.com and see if there is a “restrictor plate” put in behind the carb to the throttle body. If so remove it and if the block on the 2.5 is the same size as that on the 3.5, removing it from the 2.5 would turn your motor into a 3.5hp.

FWIW I just went looking on that site and compared the Mercury 2.5 and 3.5hp 4-stroke carbureted model schematics. They both use the same carburetor, the same main nozzle, and the same gaskets going to the intake manifold.

Usually that is where they put a restriction, or restrictor plate, with the intent that ‘less air = less horsepower’. I can’t see what they doing for the difference between the two models in regards to horsepower … but it is very common on small OBs that the “smaller one of the same block size”, etc. is de-tuned.
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Thanks Dale for the reply, I 100% agree more is better so it is betwwen the 3.5 and 4hp. Now would I notice it between the 3.5 & 4hp, probably not.
I am looking for a new engine so I will want to keep the warranty in tacked so no messing with the carb etc.
The only thing then is would I use the reverse on the 4hp often and would it be worth the extra $
I vote yes for reverse.

My boating is to support my fishing habit. I get into some tight spots back in the coves and inlets on the lakes I fish. Also, when I'm out in more open water, I'll often position the boat using reverse. I'll also fine tune the position coming into the dock by shifting in and out of (forward/reverse). That's particularly important when it's windy. I can shift as needed without looking back at the motor, and without having to contort myself around to spin the motor 180 degrees. There are times when I need to back-troll, though admittedly, that's not my favorite thing to do.

I know you can use the 360 degree steering feature on the 3.5 to reverse course. But it would be very awkward to me to have to spin that motor to reverse the thrust.

Now...how much is that ability worth? A quick look at online outboards shows the price difference is about $250-$350 dollars. I think I'd spend the Benjies and get reverse. But that's just me. Thanks for allowing me to help spend your money. :LOL:
Thanks Ray.
Its good to hear peoples experiences and some of the instances you mention I would never thourgt I would need revers for and I did think it would be a little awkward with the 360 steering.
To tell the truth, I'm also a fan of a little bit bigger motor. The downside to a motor 8hp and larger is that a fuel tank would be required and that takes up more precious space in a small boat. The cost/benefit calculation becomes more complex.
I've got a 4hp an 8 hp and a 9.9 4 stroke and I never use the 4 or the 8 always the 9.9 even when portaging into other lakes 2 people and gear and anything under 8hp just too slow for me. The 4 and the 8 are 2 stroke by the way.i use my 8hp on my canoe lol thing hauls butt!
I had a little 5 Hp mercury, and it was a sweet little motor with built in fuel tank. Purred like a kitten.

But once I went up to a 9.9, I can't believe how much more useful time I got on the water, not slowly crawling from spot to spot. Having a 2nd person on the boat wasn't a big deal, whereas the 5 HP would really bog down.

IF you have any friends with small motors you can try, you should before pulling the trigger.
I ran a 3.3 2 stroke mercury on a 1236 Jon and loved that combo. Would go about 11mph. No complaints here. Added transom wheels so I could put it on a small utility trailer and just wheel it about like a kayak.

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