Outboard on tinny

[afroboy]

Hi guys,

What do you think is the maximum size outboard that can be put on a 3.4m tinny. Mine is a Savage Gull.

It currently has a 9.9hp but I was wanting to bolt on something a bit bigger.

As I understand, a lot of the 15hp outboards are very similar to the 9.9's... some are identical other than having a larger the carburettor. So I figure there would be no probs with a 15.

But, what do you think about a 20hp on a 3.4m Savage gull? Would that be ok?

The hull is an oldish one (1980's) but is in perfect condition... it doesn't have a rating plate on it for max recommended outboard.

Cheers!

[joey_1987]

I would think you should try and contact Savage and find out the maximum hp for your hull. Personally, I wouldn't put a 20hp on it because a lot of 20hp are in fact derated 25hp's and they weigh about 40% more than the 9.9-15hp's. Some 15's will give more power than others too, the Yamaha 15hp and Tohatsu 15hp are two of the most powerful 15hp's available and 15hp Johnson and Mercury (non super) are less powerful but run smoother, this is due to the Yamaha and Tohatsu being loop charged and the Johnson and Mercury having cross flow induction. What model 9.9hp do you currently have? Even consider the 18hp tohatsu, also very very good power-weight ratio. Joey.

[afroboy]

Thanks for the reply Joey.

I have a 9.9hp Evinrude... 1976 model. I would just like something a bit quicker!

Do you know anything about the 20hp Mercury's? Are they a heavy motor? The reason I ask is because there is currently one for sale in the trading post.

Do you know anyone selling a 15?

[joey_1987]

Hi, depending on the year, it is very likely that the 20hp Mercury is a derated 25hp, weighs about 50kg's, the same as my 30hp motor. They are a heavy motor, especially for your boat. Mine is on the back of a 3.95m stacer and it is almost too powerful. I don't know anybody selling a 15hp, but they pop up quite often. Do you need long or short shaft? I can keep an eye out for you. How much do you want to spend? Joey.

[afroboy]

I'm pretty sure I need a short shaft.

I recently hit a rock with my Evinrude and now need a new drive shaft... been priced a couple of hundred bucks to fix so if I can hook up a 15 or a 20 in the next couple of days I'd rather put that couple of hundred towards the bigger motor. I was planning on buying something bigger when one came along at the right price but now I need one quickly or I'll just spend the money fixing the Evinrude until I come across a 15/20.

I'm only looking for something cheap but must be reliable... last week when I sheared the shaft was the first time I had to use the paddles... and I certainly hope it's the last!!! LOL

I can't survive without my boat as I'm seriously hooked on fishing now!

[finga64]

I have a 15 on my 3.75 Edgetracker and it goes good enough for me.
1 up gets 43 km/h
2 up gets 38 km/h (after a retrim )
3 up get 36km/h.
20 would be over kill a tad (but lots of scary moments )
I used to have a 25 Tohy and I'm happier with the 15. Easier to steer and everything else.

[saurian]

Afro,
Next door neighbor had a gull with 15 hp johnson, it flew.
He used it as tender and a beach launcher on 4by4 trips.
I do not think it would handle 20 hp.
But put some extra bracing on the transom and put it on......
But be warned speed kills....
The other side effect may be a dump wave as you come off the plane
Which is manageable , but after a while it just pisses you off.
Personally , 15hp merc , beatiful.

[2iar]

I used to have a 3.4 tinny.

I reckon a 15hp (assuming you're hull's rated for it) would be perfect. Nowadays, 9.9's & 15's in each brand weigh exactly the same. With the more modern ones, you'll probably find that you'll actually have a lighter motor in a 15 than your current old one in 9.9.

Your new motor will do the same speed much easier than your 9.9 at WOT, and of course give you a better top speed/hole shot.

My gut feeling is the 20 is too big, you'd have too much weight at the back for a start, and you'd be adding extra weight for little gain, even if your hull could handle it.

Good luck,
Mike

[afroboy]

Guys, I really appreciate your advice, thanks!

Yeah, I suspected that a 20hp may be a tad heavy. But what can I say, no matter what it is that I own, I want to go faster!

Does anyone know of a 15hp presently for sale?

I can't believe this a long weekend and I can't go fishing!!

[mr_Z]

mate i'm looking at getting a 3.75 dart which i will be putting a 20hp honda on (the boats max rating)

all the 3.4's i've looked at have 15hp yamaha's, which would be perfect on a boat of that size

cheers

[mally]

mate i had a 3.4m tinny with a 2003 short shaft mercury 25hp, i had no problems with it at least u never have to go full stick

[bidkev]

<snip>Mine is on the back of a 3.95m stacer and it is almost too powerful. <snip>

Yeah, got a 25merc (tiller gear) on my 3.95 stacer...........I wouldn't like to go any faster

kev

Laughing at our mistakes can lengthen our own life. Laughing at someone else's can shorten it!

[gunnabuild1]

afroboy I've got a Stacer 3.1 [11ft in the old money] and its rated up to a 20hp it's a real old tinny dont know that I would want that much on it BUT it only goes as fast as you tell it to after all.Just got myself a 15hp yammy trying to find time to try it out.
Time and Money the only things I dont have enough of!

[gunnabuild1]

Yes afroboy I did get the 15 hp off Keith like I said looking forward to using it.
[I cant send you pm dont have enough posts]