Thread: Power boat for the young fulla

Originally Posted by Chris

Think regards the shaft length the longer the shaft the deeper the V but not positive on that.
Think Mariner ,Yamaha are rated at prop ,don't know about all modern motors.
From memory the prop rated motors like adding another 5 hp .?

Johnson/evinrude changed from flywheel rating to prop rating around 1988 j140hp at the flywheel now equals 115 shaft hp. the trim plate at the top of the skeg needs to be parallel to the keel at half trim the height of the transom will be determinded by the length of the leg (mounting bracket down to trim plate) the trim plate may only need to be 10-20mm lower then the keel. if set to high you will lose trim and also you will ventilate the prop losing power and posablly depriving the leg of water and running your cooling impeller dry.

Originally Posted by mucko

Johnson/evinrude changed from flywheel rating to prop rating around 1988 j140hp at the flywheel now equals 115 shaft hp. the trim plate at the top of the skeg needs to be parallel to the keel at half trim the height of the transom will be determinded by the length of the leg (mounting bracket down to trim plate) the trim plate may only need to be 10-20mm lower then the keel. if set to high you will lose trim and also you will ventilate the prop losing power and posablly depriving the leg of water and running your cooling impeller dry.

Your a legend Mucko, I'll be able to design the whole ass end of the boat off 1 paragraph.

Only rule with boats is the same as cars HORSEPOWER ----------- lots and lots or you will be disappointed long term

Listed outboard on TM. Yamaha 15H 2 stroke short shaft | Trade Me

Since I'm such a nice guy 10% discount off final bid for forum members

Originally Posted by big_foot

Listed outboard on TM. Yamaha 15H 2 stroke short shaft | Trade Me

Since I'm such a nice guy 10% discount off final bid for forum members

Is that not F.N.R selector on the side of the engine in pic 1

looks like someone has spent shitloads on it.

Originally Posted by mucko

Is that not F.N.R selector on the side of the engine in pic 1

looks like someone has spent shitloads on it.

Lucky I have the wisdom of you guys behind me

Yea shes tidy alright aye almost vintage

Cheers mucko

Originally Posted by big_foot

Lucky I have the wisdom of you guys behind me

Yea shes tidy alright aye almost vintage

Cheers mucko

just thinking about it at milking thats a 70's 15hp that will = about 10 shaft hp in a post 1990 outboard