yamaha f100 vs f115

[zod550]

i currently have a 5.5 meter zodiac with a f100. i have had the motor 4 seasons (600 hours) and i want to repower. I feel that the boat is slightly underpowered with the f100 (top speed 35 knots) and wonder if i would see that much difference with the f115. Does anyone have a f115 on a similar boat? looking forward to your replies. Chris

[eksrae]

wait for the 150 4 stroke that will make it move

[Islander]

The F115 is a superb motor, very smooth instant power and does not compare to the F100 at all. We have had both.
The F150 is available now as I have seen several already fitted to craft here in the UK.

[Scotty]

I have a mercury 115 two stroke on the same boat and it goes like shit off a shovel. Go for it !

[Petrov]

I think you should go for the 115, the diffrence between a 100 and 115 is that the 115 is an injection engine and the 100 is an carburator engine, with the right prop you should point at 40 knots, the weight of the 100 is 164 kg and the 115 is 195 kg, wich means that the 150hp will probably be a little bit to heavy for a 5,50m boat (around 211,3kg) does`nt sound much but after the transom the weight effects the boat more than inside the transom, maybee even the 115 will be to heavy, check with Zodiac before doing anything, in worse case the boat will go even worse if it`s to heavy, offcourse you can compensate with weight in the front but that`s not an recomendation.
Also the difference between the engines is that the injection four stroke almost has an acceleration of an two stroke engine.

Good luck

Regards

[Alex Brown]

Have you considered the Suzuki range of 4-stroke outboards? - the 140 for instance weighs less than the 115 Yamaha if I remember right.... it's also deadly quiet when running at lower revs, and the 90, 115, and 140 suzuki engines are all efi by standard anyway.

Just a thought

-Alex

[TIPS]

Hi,
we've got a Yammy 115 four stroke on the back of a 5.6m Avon adventure (up 4 sale), the engine is ace, extremely quiet and smooth, acceleration is also very good. we use about 20 litres for a good days use, thats with watersports as well. Top speed is around 42 knots 1 up on the absoulte carm, at around 5800 rpm. it will go higher but I won't rev it any further until it has a more suitable prop.
We use about the same amount of fuel, if not slightly less that our 2001 mercury 60hp 2-stroke on 5m Zodiac YL.

I probably wouldn't upgrade to the 115 tho if I was you though, I doubt you will see a considerable increase in top speed that justifys the additional expense. If you do though, opt for a different prop than the standard 13inch, 19 pitch ally prop.

Mark