AVON SR 4.7 & 90 HP suzuki 2009 4 stroke

[njensen]

My 1998 4.7 Searider is currently mounted with a 65hp 1998 suzuki. When waterskiing (+80kg persons or starting on one ski) or carrying 4 divers with twin tanks and stages (+300kg equip, 320 kg persons, 50 liters of fuel, ancher, A-frame, Steering console, ect.) the boat seems a bit underpowered. I had it 11 years so it's definately not a "show-stopper" but more power in those situations would be very nice. I rarely or never do any high speed sailing since i use a relatively small propeller and mainly use the boat for diving, fishing and water-skiing.

for several years i've considered to mount a 90 hp engine allthough i'm aware that is only rated for 70hp. To keep the weight down a Tohatsu 2-stroke 90hp (TLDI) could be an option (146kg). Lately Suzuki came out with a 90 hp 4-stroke only weighing 155kg. This is 38kg lighter than their previous model which i believe is way to heavy.

My current engine weighs 113 kg. I can't find the max weight rating for the SR 4.7 meter anywhere.
The 5.4 meter Searider is classified for 90hp or maximum 175 kg
The transom on the SR4.7 and the SR5.4 are the same. So i guess it's not an issue about the transom cracking up but more a stability issue.

The Seariders has the open hull system for better stabilty at idle but i've closed those holes with inspection hatches to overcome the underpowered engine. I guess with a larger engine i could start using the ballast system as it was intended.

Buying a bigger boat is not an option at this moment. I'm happy with the size of mine and it's in perfect condition.

Under the circumstainces mentioned do you think it would be crazy to go for a 146 or 155 kg 90 hp ?

Has anybody tried to overpower a Searider (4.7) ?

[Downhilldai]

4.7 Searider is rated 285lbs (approx 129kg) max transom weight.

[njensen]

Yes i know it's past the ratings. Found the text below in another thread...
why does it take more weight on the transom if it's a ultra long engine shaft ?
Does the balance get better using a ultra long vs the long ?

I intend to go out at try it "real life".. I will add the extra approx. 40 kgs (155-113) to the transom and see how it handles with 1 person. I guess if it handles ok empty (1 person) it should be perfectly ok when it full of diving equipment. I don't have any problems with water coming in at idle not even when the boat is totally loaded.

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QUOTE (other thread "engine to big ?" )

Got an email back from Avon.....

There is a maximum 70hp for the SR4.7m Searider.
The maximum transom weight would depend on
if it is a long or ultra long shaft.

The long shaft is standard for this boat.

Maximum Transom weight
Long shaft 130kg
Ultra long shaft 150kg
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[Leo]

I've had a similar problem: on a Joker 470, the max. hp is 75. I think that the weight was the problem when they developed the boat. With the new Suzuki different times arrived on the weight issue’s. So I bought the new 90HP and I can tell you, it’s great!! No problem and a great handling, speed and so on. So don’t be afraid, do it!

(keep in mind, when you are trailering, put the weight of the transom with a strut under the tail of the outboard. That’s the reason that transoms crack. Most people forget that.)

[njensen]

Hi Leo

It looks very nice :-)

How do you support your engine during transport ? I don't fully get it..

Are you sure that is needed ?

[spartacus]

Originally Posted by njensen

Hi Leo

It looks very nice :-)

How do you support your engine during transport ? I don't fully get it..

Are you sure that is needed ?

Use an engine support when trailering. Seem to be big in the States, but they're catching on over here too. Basically it's a galvanised steel extension which runs from the trailer to the lower leg to avoid engine vibration and absorb some of the shocks while in transit.

[Leo]

I've made one out of wood, you can see it on the photo (not in his place however). It's very simple to make and if it's wood, it won't damage your tail. If I find the time I will make a photo this weekend.

[Leo]

And here he is, took me about 30 min. to make, simple and effective .

[njensen]

thanks a lot for the pictures....