30hp outboard on a sib marked as a 25hp max?

[kaman]

Originally Posted by 69cmw

Yes, twice over the last 16 years, both times they paid out satisfactorily and that was for 2 theft claims.

You've been very unlucky yo have suffered two thefts!
But very lucky that the insurance has coughed up - twice!

[m chappelow]

One advantage of the older type boats that had wood or Ali floors & Thrust boards fitted is the power force of the engine acting against the transom was partially transferred to the floor board which in turn acted on the forward Thrust board up in the bow quarters taking a lot of the stresses from the transom joints .

[Adamn]

I have been reading this debate with interest?
I owned a Honwave 3.8IE with a Honda 20 4 stroke it weighed 46.5kg. It was very fast with one person in and comfortable with 2 to 3 in.
I have several questions I am sure people will be able to answer.

1. 2 strokes are much lighter than 4 strokes?
2. Sibs are generally lighter in build than they were?
3. Old engines were power rated to what they produced at source. Now the power is rated from the prop so an old 30 could have the same power as a new 25 at prop?

If these questions are right that may answer the lower power on newer boats.

[dave3235]

Originally Posted by Stevenmb

I'm just curious but I recently brought a 30hp outboard. I'm looking for a sib but a lot of the newer sib's are marked up to 25hp. Surely if 25 hp engines and 30hp are effectively the same there should be no problems that arise from it while at sea? Also curious if I put it on a sib marked as a 20hp max on transom. My budget is limited. I currently have it ready to go on my avon sib which is rated up to 40hp but the inflatable keel has given up with multiple leaks in hard the patch areas .
Any advice would be great
Cheers Steve

Take a look at sib transom strengtheners by Matty wood in archive

[Max...]

Originally Posted by Adamn

I have been reading this debate with interest?
I owned a Honwave 3.8IE with a Honda 20 4 stroke it weighed 46.5kg. It was very fast with one person in and comfortable with 2 to 3 in.
I have several questions I am sure people will be able to answer.

1. 2 strokes are much lighter than 4 strokes?
2. Sibs are generally lighter in build than they were?
3. Old engines were power rated to what they produced at source. Now the power is rated from the prop so an old 30 could have the same power as a new 25 at prop?

If these questions are right that may answer the lower power on newer boats.

1. Lighter and quicker on take up. Some low powered engines are closer in weight,

2. Generally but plenty of built like a tank old Avons around if you want to go down that route. Zodiac still make lots of heavier duty SIBs too. Endless choice out there for everyone.

3. I have read that but I think you have to go back a while.