Shetland family 4 mk5 engine

[rors]

Hi All
First off i would like to thank Cameron and dave at Clyde-outboards i can,t thank them enough as they have been very patient
with me .
So here is my dilemma I was going to buy a used 90hp honda for my shetland family 4 but then just before the deal went though i was told that the engine was to big and heavy for my boat .
so i rang shetland boats but they could not give me a straight answer they humm and haud yes it might work but could not guarantee it would not take off the transom.
As its an old boat they did say how ever that a 80hp was the max that boat would take but did not know what weight so now i am confused
can any one tell me the correct engine for this boat Shetland family 4 mk5.
All i want to do is bring 4 children out and maybe use a ring for an hour or so and then do a bit of fishing on inland waters and maybe on the sea
but i want to do this as safe as posable.
So thanks again to Cameron and dave at Clyde-outboards they are the best and i cannot recommend them enough.
But can any one please advise.

Thanks Rors

[splashmountain]

We have just fitted a Mariner 75 Optimax on our Shetland Family 4 Mk5 which weighs in at 170 kg. So far so good. James at Shetland Boats said that there would be no problems. But we have never been able to find out whether it is the hp or the weight that is the important factor.

[rors]

Hi splashmountain
The honda 90hp i think it weights in at around 170kg.
I would all so love to know whether it is the hp or the weight that is the important factor
Dos your 170kg engine make the boat sit deeper in the water?
If you could give me as much info as possible that would be great.
Also have you any pics of it as i would love to see it .

Thanks for all your help Rors

[johnhalls]

I could understand you wanting a 90 hp engine weighing 163 kg if your interested in big engines but if your interest lies in boat performace why do you want such a monster. My Mariner 60 big foot ( weighing 112 kg) pushes the family 4 onto the plane at 12 kts and gives me more speed than I need at the top.

I'd advise you to think again Rors

[rors]

Hi johnhalls
When you say your engine pushes the family 4 onto the plane at 12 kts.
How many people are you carrying at the time.
As i would be carrying 3 to 4 children and my self would the 60hp still plane with that many?
Appreciate any help.
Thanks Rors

[colinpearce]

I would consider a smaller 2 stroke too, they seem to have better acceleration and lighter than the 4 strokes but noisier, smokier and thirstier. We have Honda 90 on our Black Hawk but there's no comparison between boats as ours is much heavier. We used to have an old Suzuki 85 and that was far better at getting the boat on the plane but for our needs the Honda is better

[johnhalls]

Hi rors,
I have to admit that this has been whilst going alone. When I used to have one adult passenger the performance was very similar, on the plane at 14 knots.
The light-weight engine is bound to make a difference.

Good luck
John

[deeandmartin]

We have mk 2 570 which is rated on the statistics as taking up 115 hp, which at the time of manufacture of the boat would have been 2 stroke, we took advice from several sources last year when changing our engine and ended up buying from Bill Higham in Manchester. We have used both 4 stroke and 2 stroke, and have to say our personal preference is 4 stroke, we use the boat both inland and coastal and like the quietness and performance that we obtain with a 4 stroke. On engine size we were looking at an 80 hp, but ended up with a 100 hp, amazingly there is no difference in weight between the 80 and 100 which remained within the parameters of the weight of a 115 hp 2 stroke, and of course the engine hp size is below the maximum of 115 hp. All of this was discussed at great length and taken on advice of people far more used to the ins and outs of these things, having used the boat with the new engine last year we have to say we are extremely pleased with the end result. Hope this helps, Dee

[splashmountain]

Going back to the original question, probably the main consideration is your insurance. Most of the older F4s had 75 hp as the maximum engine size, so if that is true for yours, then you shouldn't exceed it or else you insurance might not be valid. I haven't ever seen a max engine weight specified for insurance purposes.

[rors]

I have to say thanks for all your comments.
But to be honest i am more worried about my Transom
would it be abel to take the honda 90hp and the weight .
just wondering if i did put a 60hp honda on it what speed would the F4 plain with 3 adults.
Just a thought Has any one seen i think it was a chart that gave all the deferent boats and speeds with different engines
some were on the old shetland site

Thanks Rors