Minimal hp Avon SR6

[Daapiedo]

Hello all, this will be my first posting on this forum. I have been following numerous threads before. I just recently purchased an 1994 avon sr6 with 2 x 60 hp yamaha's 2 strokes from around 2000 on the back. I'm looking in to repowering the boat. I found an great deal on a yamaha f115 efi with very low hours. I'm just not sure if 115 hp would be sufficient. We would be using the sr6 mainly for long distance 2 person trips.
I would like to hear your opinions.

[Bushrider]

My SR6 came as well with 2x 60hp 2 stroke Yamahas and honestly - the boat felt pretty happy with them . Only thing I was not happy about was the fuel burn and thats why I changed them for 2x 90hp ETECs .
I would assume that the 115hp would maintain a similar speed as you achieved with the 60s (my was 30kn with 17" alu props) .
Hole shot might suffer in comparison to the 2 strokes .
Do you have a flooding hull ?
If so to get on the plane I would expect to be sluggish with 115hp 4 stroke .

[Daapiedo]

Thanks for your response.
My Sr6 is an none flooding one.
My main focus would be economy. I'm would like to be able to make 100 Mile trips without bringing enormous amounts of fuel. I mainly cruise at planing speed and top speed isn't really an concern.
Could you comment on your fuel burn with the 2x Yamaha's?

[Searider]

Originally Posted by Bushrider

My SR6 came as well with 2x 60hp 2 stroke Yamahas and honestly - the boat felt pretty happy with them . Only thing I was not happy about was the fuel burn and thats why I changed them for 2x 90hp ETECs .
I would assume that the 115hp would maintain a similar speed as you achieved with the 60s (my was 30kn with 17" alu props) .
Hole shot might suffer in comparison to the 2 strokes .
Do you have a flooding hull ?
If so to get on the plane I would expect to be sluggish with 115hp 4 stroke .

I'd agree with all of that but add that a larger engine working less hard might make better economy.
The 150 optimax on my 6.5m is burning less than a litre per mile up to about 26/27 knots.
I'd tend to suggest a little more power than 115hp.

[Daapiedo]

I also found an spotless 2007 yamaha 150 hp 2 stroke. Its an Carb model.
How fuel efficient would this be in comparison to the f115?

[Bushrider]

Originally Posted by Searider

a larger engine working less hard might make better economy.
.

No doubt - my comment regarding the high fuel burn was connected to the Yamaha 60s .
For 33Nm I filled 65 liters is ..

[95gstnj]

If you want to go more than 20-23kts wot I would strongly recommend a 150hp on an sr6. Its perfect for the hull.

Also I have had twin 70hp on another sr6. Significantly slower and much more fuel consumption. Also, with one motor trimmed out of the water it struggled to get on plane on a single 70hp lightly loaded.

[Ferryman]

Totally my opinion, the old Yamaha 2 strokes were very reliable and very thirsty! I’d go for around 150hp from a major manufacturer as new as you can get.
The 115hp would be fine but you are aiming for fairly long distances - trying to get home into a headwind, you’ll love the extra hp!!