Outboard sizing

[TomTom]

I am building a P19 in Australia.

The boat and trailer will cost about $8k, however a 90 hp outboard (recommended) will cost close to $16k fitted with gauges, looms etc.

Can I get by with say a 60 or 70 hp, which are much cheaper ?

It would be great if we had a table of different horsepower with speeds at different revs for each, e.g. a 70 hp will give 25 knots at 4000 revs, and 18 knots at cruising revs.

Guess I will need to look for low hours second hand engines.

I had a 90 FICHT Ram on my C19 - they are a very similar hull. It was just right. But would not go for anything less except possibly the old Yamaha 85 2 stroke would have been ok. If I lived in your part of the world I would keep my eyes open for a good second hand engine that had been used in freshwater - but not less than 90HP

[grundasaurus]

We built a P19 with a yamaha 115 four stroke, our boat is significantly heavier than plans, but it feels perfect with the 115, cruise at 30mph at about 4200rpm with a flat out speed of around 37/38 or so. The 115 weighs almost the same as the 90 so if you can find one in your budget I wouldn't hesitate to go for the extra power. I would suggest adding a fin or those smart tabs though as our boat at least definitely needs a bit of lift, and tends to porpoise if you trim the motor up at all.

[TomTom]

Second this - I reckon a Yamaha 115 would be the perfect size!