What size of engine for 3.1m

bbjunkie

Cadet
Joined
Mar 1, 2009
Messages
17
Hi

I have a Wetline/Waterline AR310 inflatable with inflatable keel/floor.

Transom plate says max motor weight 50kg max power 10hp

Currently I am using a 4hp which isn't strong enough to get it past 5mph at WOT. (lifts the nose real high when im in it on my own, doesn't seem to have enough power to lift the stern out of the hole)

Would there be much difference between a 8hp and 10hp in speed? Also, would there be much difference if I was to go to 4 stroke? (I know 2 strokes are lighter)

Usually there would just be two of us and some fishing stuff in the boat, approx max 400lb of people and stuff.

Great forums here btw

Cheers
Pete
 

Howard Sterndrive

Rear Admiral
Joined
Nov 5, 2008
Messages
4,603
Re: What size of engine for 3.1m

I would put a 9.9 on it. Inflatables work best when powered to their max.

2 or 4 stroke just a personal choice, and probably better discussed in this forum:
http://forums.iboats.com/forumdisplay.php?f=16
but ask about various angles you can store the 4 stroke. Some need to be laid down a certain way and for a tender or boat that is deflated frequently or mini-van'd to the lake, this can be a factor.
Local reg's on 2 stroke use also a factor.
 

bbjunkie

Cadet
Joined
Mar 1, 2009
Messages
17
Re: What size of engine for 3.1m

I would put a 9.9 on it. Inflatables work best when powered to their max.

Decided to go for a Honda BF10 - Great engine!

Now if I can get the prop to actually grip the water i'll be all set - It's loosing grip when engine reaches 3500-4000 rpm (9-1/4x9)

Pete
 

flwestcoastboater

Seaman Apprentice
Joined
Aug 22, 2008
Messages
49
Re: What size of engine for 3.1m

I had that same problem with a 5hp on a choppy day in my inflatable. Never solved the problem, got a new motor for a sailboat too :)

The honda 4 strokes work very well! I have had a bf5 for a while now, besides a gas fitting issue, it has been trouble free for me. The 10hp must plane the inflatable very nicely!
 
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