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jha190
09-01-2016, 01:13 PM
Hi guys just wondering what the best size motor for 12.5 Inflateable (rated to 25hp) would be? any thoughts would be appreciated

Safety D
09-01-2016, 03:39 PM
15 horse all the way. A Honda

bwackwabbit
09-01-2016, 03:47 PM
20hp Merc 4 stroke short shaft
w/hydrofoil

Cheers,

Scott.

Okotokian
09-01-2016, 03:58 PM
Rated for a 25? Get a 25.

bwackwabbit
09-01-2016, 08:19 PM
You would think so but with these boats they don't so much glide through the water as much as they PLOW through it. The difference in weight between a 20 and 25 is substantial and getting on plane will be a challenge.

20 is the best balance of power and weight as well as being easy to tilt up or down while in the boat. You will be doing this a fair bit until you find the "sweet spot". Also one of the big benefits of an inflatable is running shallow, make sure you can manage the 25 if you do go that route.

Either way you will enjoy the power.



Cheers,

Scott.

EZM
09-03-2016, 06:17 PM
You would think so but with these boats they don't so much glide through the water as much as they PLOW through it. The difference in weight between a 20 and 25 is substantial and getting on plane will be a challenge.

20 is the best balance of power and weight as well as being easy to tilt up or down while in the boat. You will be doing this a fair bit until you find the "sweet spot". Also one of the big benefits of an inflatable is running shallow, make sure you can manage the 25 if you do go that route.

Either way you will enjoy the power.



Cheers,

Scott.

Totally agree ...........

A Honda 20 hp would be my choice. Light at 103lbs and bullet proof reliability.

lsxfirebird
09-03-2016, 07:29 PM
What size inflatable? I have a 25hp etec on my zodiak and its perfect size

Redneck Tommy
09-03-2016, 10:48 PM
If your buying new I would go with Suzuki 4stroke there 15,20,and 25 horse are all the lightest in there class.on the used market nothing beats the old Evinrude 15hp 2strokes.

EZM
09-04-2016, 12:20 PM
If your buying new I would go with Suzuki 4stroke there 15,20,and 25 horse are all the lightest in there class.on the used market nothing beats the old Evinrude 15hp 2strokes.

Those are a decent choice - the 15 and 20 hp are 97lbs - light.

Keep in mind, like all manufacturers the 25 hp jumps up in weight by another 46 lbs weighing in at 143lbs.

That was bwackwabbit's point ...... going up to a 25 hp (with virtually all manufacturers) adds a bunch of weight (like 40-50 pounds to a 100lb engine) - so portables really are limited to 20 hp unless you are capable and willing to wrestle some extra weight.

To most guys the extra 5 hp isn't worth the extra weight. You don't get a huge amount of advantage here - but you sure as heck get a better workout.

bwackwabbit
09-04-2016, 01:06 PM
The extra weight is a direct hit to performance IMO.

Having used both personally on a Seamax of similar size. I found the 25 would cause increased cavitation and the transom would squat badly during hole shot causing increased drag from the portion of the pontoons behind the transom. Getting up on plane w/one guy in the boat took nearly 12 seconds. I tried multiple configurations of fuel tank location, gear placement etc. to keep the nose down with little to no improvement.

The end result was a top speed of 22mph @WOT regardless of trim.

Switching to a 20hp (both Merc 4 strokes) made a huge difference.
Although it did still squat heavily on hole shot it was quickly up on plane (6secs or less) and by moving the fuel tank up front dropped that to 3
secs).

End result of this setup was a top speed @WOT was 31mph and reduce fuel consumption of approx 10%.

The best results were achieved by first sitting the boat in the water loaded (have someone with you to guide you on this step). Adjust trim setting until the motor sits level while loaded.

Cheers,

Scott.

jha190
09-09-2016, 02:07 PM
Thanks so much for the input. If any of you know of any 20hp motors for sale preferably northern alberta let me know. Thanks again

bleedscrestliner
09-14-2016, 03:57 AM
if you looking for a 20 hp, short or long shaft. pm me??

Don K
09-14-2016, 08:30 AM
If you can find a 2-stroke, oil injected Yamaha 30hp you will be thrilled. I had one on a 14' I sold and it got up and went. I have always went slightly over the rating and NEVER been disappointed. The ratings on some of the new boats are ridiculously low...

Legend Boats
10-02-2016, 06:16 PM
I think the most efficient outboard you can get on that package is a 6HP. It will allow you to keep the weight down and doesn’t require an external fuel tank. Typically you will have a built in fuel tank capacity of 1L but on a 4-stroke you can go a couple of days before refuelling. Hope this helps

Cheers Henry