What size of lump

[spicer]

I currently own a Shetland 570 with an Evinrude 60 on the back. After much considering I have decided to change the engine to someting with a bit more get up and go. My two choices so far are either a Yamaha 90 or 115, both being 2-stroke, but is it worth going for the larger or is the 90 'quite sufficient.'

 

[tcm]

Hmm, unfortunately this question asked aroud chucking out time in stamford.

Soo, my advice to get a most massive lump affordable an/or imaginable. I saw a yamaha 220 at the boat show with "vmax" or "double injection" or something like that, so get that. After all, a 60 hp quite weedy engine and even 90 hp or 115 still only repmobile sort of car.

Seriously, at this sort of size a half decent supplier may be able to temporarily rig up a s/hand unit as a trial?

 

[Guest]

I think max for this boat is a 115hp, so go for that. You can always use less throttle to go slower !!

 

[tr7v8]

Some of the Shetlands have a 90HP limit others have a 115HP, I'd ask Shetland because my insurance Co. a few years ago got very excited by an engine they thought too big for the boat.

Jim
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[jfm]

I have run those hps on several 5-6m boats and I would think you wd get say 33kts with the 90 and 37 ish with the 115, with say 2 people on board.

I would always go for the larger one. Wouldn't worry too much about manuf recommended limit, within reason. Make sure the transom is in good nick, the main issue with a larger hp is weight as you go over bumps in the road, it puts a lot of stress into the transom. With the larger one you might cruise at 3000rpm rahter than 3700 and the noise is then much better on long trips

In a 2 stroke, and in that partic HP rating, the Yamaha is an excellent engine imho. The other contender wd be the Mercury 2 stroke. not the 90, the 115. And then you might as well get the 125, as it's the same size/weight as the 125, and same cost if shop around. You should be paying a bit under £5k for the 115s.

 

[jacksong]

I have a Shetland Kestrel, so basically the same boat, which until this year had a Evinrude 50 on the back which could propel it along well enough but was noisy, thirsty and used to struggle against the tide in the Bristol channel.

So given that it was rated for 115hp I went out and got a nice new Yamaha F100B four stroke. The boat now moves along at a very nice rate of knots, is very very quiet when idling and uses a whole lot less go juice. Only problem I have now is that I can't get the all weather cover on because it won't fit over the new engine.

I went 4 stroke rather than two for the quietness and fuel economy and I'm very happy with. Given my experience with the power I'd say that the 90 is more than enough unless you want just that bit extra grunt and a few extra knots on the top speed or unless you have a powerful tidal stream to fight like I do.

J

--
I am not a Frog, I am a free Womble

 

[Col]

Couple of years ago, I saw a Shetland blackhawk with a 175hp moored at the Jolly sailor, on the Hamble. The guy said it went like s**t off a stick. Don't know if its still about.