Engine Upgrade

[cornish_ribber]

Hi all

Like some advice please. I have a 4M RIB rated at 40hp. It currently has a Tohatsu M25C3 uprated to 30hp mounted. I have got a new two stroke Tohatsu M40D2. The relative weights of the engines are:

M25C3 51kg
M40D2 72kg

My question is - could I just swop engines or should I install some transom strengthening bars first.

Thanks

[spartacus]

If the boat is rated for 40hp, then you shouldn't need to reinforce the transom. Take a closer look at the boat serial plate, it will have a maximum permitted weight for the outboard.