Any small outboard experts here?

[capnjim]

So I figure TB has many experts in many area's and I need some outboard motor advice.
I have a 12' intex inflatable boat, not a zodiac type-no real transom.
It can't take more than a 40-50lb motor. I am currently using a 1992 Suzuki DT-2 2hp. Nice little motor,2 stroke 2cylinder 25lbs, but she doesn't move along very quick at all. As much as I would love a newer 4 stroke, they are all too heavy and way out of my price range.
I found a 1988 Johnson 4hp which is a 2 cylinder 2 stroke, weighs 50-60 lbs.
My question is whether or not this would move my boat significantly faster. Its double the HP, but an extra 30lbs or so.
Probably a longshot asking here, but its not like I can try the Johnson out.
The guy bought the Johnson new in '88 and says it looks and runs like new and he used it maybe a dozen times.
I don't want to spend 400$ that I can't really afford and end up being disappointed.
Thanks TB!!

[FL Knifemaker]

I really don't think you'll see much improvement unless you jump up to a 10hp. The newer 10hp outboards are VERY refined and VERY light for their size. Yes, a new one is expensive but they last forever. The other options is find a used 10hp or the older 9.9s. Even an older used one would really make that boat move compared to the 2 or 4hp.

[tiz_1]

They have a strange website. The length of the boats and rated hp they can carry is not listed for most if not all of the boats.

FYI I was a certified Johnson/Evinrude mechanic in my youth. Have owned boats for 30+ years.

Since I can't see exactly which boat it is I'd say the following:

1) there SHOULD be a 'rating plate' somewhere on the rear part of the boat that says how much engine hp and how many people it can carry. Refer to that first. If 4hp is ok, it is worth a try.

2) the boats all look to be 'displacement' boats. That means the hull shape is either not suitable or not capable of supporting the boat on a 'plane'. Planing is when the boat skims over the water vs pushing through it. Planing is fast, displacement is not fast.

3) the type of engine mount these use can be overwhelmed by too much hp and 'fold' the boat. It happened to me on a sevylor inflatable with a 5hp on it. Scary.

Bottom line is yes, you can hang more hp on it and go faster. Whether the boat is safe while doing that is another matter. Also $400 for that motor seems a bit steep. I got a more recent 3.5 nissan for $325 a while ago.

Good luck. Wear a pfd or at least carry one while you're experimenting.

--Kevin

[turbo chicken]

Cool i just learned something about boats ... I love this place!

[FL Knifemaker]

Originally Posted by turbo chicken

Cool i just learned something about boats ... I love this place!

Another consideration is that speed on the water is very different than speed on land or in a car. Yes, you are actually going the same speed but........

A boat that will creep along at less than 10 mph will take forever to get anywhere on a good size lake. Jump up to just 20 mph and covering that same good size lake isn't all that bad. Go 30mph and just about anything is possible. My boat with a 115 will run right at 50 mph which on the water seems damn fast. For the lakes I fish, it's more than enough. Jumping up to a boat that will do 60mph is like a rocket. A full blown tournament bass boat that will do over 70 is like light speed!! So the range of speed and what it will do, how much distance it will cover and what it costs to do it are VERY broad. Bumping up to a 10hp from 2hp will be a HUGE increase in speed and the range you can cover.

[capnjim]

Thanks Kevin.
It does say 38lbs on it as a rating. My Suzuki is 25 lbs and it doesn't even "bend" the mount a tiny bit under full throttle. I figure 50lbs would be a safe max.
No way can I get a 9.9 under 50lbs!
Welcome to Intex Recreation
Here is the exact model, its pretty heavy duty and has a solid floor, its easy to stand and walk around. Also has 5 air chambers (Counting the inflatable keel)
The Johnson may be a bit steep, but the seller claims it is like new.
Do you think the Johnson will move it a lot faster? Thanks for explaining about planing. I never really knew that. The boat will probably not plane, so the 4hp may not "push" it noticeably faster?

[fhm555]

The best way to compare the relative power of the two motors in question is to compare operating RPM and prop diameter/pitch. I'm guessing you will find a larger diameter prop on the bigger motor, but the RPM and pitch will be real close to the same. What that means is the bigger motor will move more weight at about the same speed.

You will gain some speed, but it will be so little you might not notice it.

Generally speaking, a move that small would be to handle more weight rather than gaining speed.

Not wanting to be the dsoomspeaker here, but if you want more speed you need a different boat.

[anonymous122511]

Originally Posted by fhm555

if you want more speed you need a different boat.

That was my first thought. I'm running a 2hp Honda on my 8' soft bottom deflatable and it just kinda is what it is. I also don't think there's much (if anything) out there in a 5+hp motor that fits the price/weight. parameters.

[fuzzy beard]

With that displacment hull more motor is not the answer! A boats speed has more to do with hull design than Hp. Once you reach maximum hull speed there is VERY LITTLE gain even when doubling HP! But if you are looking to spend money another more efficant prop may help some. But i dont think you will get much more out of it no matter what you do.

If you want to go faster get a planing hull! And a matching motor for that boat!

[Downunderwonder]

If you put 60lb motor where it ain't supposed to be, with just two adults right down the back, you might get it to plane, or you might need your lifejackets. Fun times.

[capnjim]

Thanks guys. I have come to my senses. I went out last night with the kids and it was fine. I think its the perfect motor for the boat (It is only rated at 1.5hp and 25lbs) and I would probably have trouble with a bigger motor, not to mention lugging and installing a 50lb motor over a 25lb motor.
I just wish I had the space for a little aluminum fishing boat....oh well, I'll try to be happy with my little inflatable.
Plus, I did get this sucker with it:


Uploaded with ImageShack.us

[R. Laevinus]

That's a mighty fine fish!

Although, I have to say, my favourite watercraft propulsion device is one of these: http://www.kayaksandpaddles.co.uk/ca...e-paddle-2.jpg