Présentation

[almetelo]

Great boscoe! Thanks
Good to know...
Always good to have other perspective on what to do when I do my motor rebuild (even if is not exactely the same thing)

[99yam40]

Seems like they could test the prop WOT for one minuet or less to make sure it gets where it should be without a problem

[zenoahphobic]

Seems like they could test the prop WOT for one minuet or less to make sure it gets where it should be without a problem

Reasonable assumption, because it implies the engine will not gain anymore RPM's after run in, that in turn means the engine is made to already run freely.

Unlike an automobile that already comes with a gear box (with a selection of ratios) connected to a load (wheels on the road), an outboard comes with the ability (need ) to attach a "gearbox" , a propeller, that only has one "gear" to apply full load.
Like all things there are compromises in design and operation. With an outboard the view is that it is designed to run at maximum (limited) RPM at maximum throttle opening (WOT). Why that is, is complex, but it has to do with having only one "gear" and the obvious reason to be able to utilise all the horsepower available.
So at some point the engine needs to be run at WOT, to determine at least the right pitched propeller that limits the engine going beyond the designed maximum RPM. The rest of the propeller selection of course is the type of "grip" and the maximum speed (efficiency) , depending upon how the boat will be loaded and used, that one will be happy with.

[zenoahphobic]

It is interesting to note, that running in procedures don't mention how quickly throttles should be opened.
The vigorous instant application of full throttle, particularly those of large horsepower, would put more strain on an engine than progressing the throttles open slowly.
How is this viewed, as I know of people that also like to run in engines with instant full power ( maximises combustion pressure to the rate of piston movement)?

[boscoe99]

It is interesting to note, that running in procedures don't mention how quickly throttles should be opened.
The vigorous instant application of full throttle, particularly those of large horsepower, would put more strain on an engine than progressing the throttles open slowly.
How is this viewed, as I know of people that also like to run in engines with instant full power ( maximises combustion pressure to the rate of piston movement)?

Excellent point. I suspect many a big block HPDI model, that is prone to detonation, has been damaged by too quickly a use of the throttle. Very large pitch propeller. Hot foot. No knock sensor. Degraded gasoline. Guys stomps on the gas pedal. Throttle is wide open while the motor struggles to come up on the RPM. Kablooey. He blames the POS motor.

Much much worse than coming up on the power gently and then running at WOT or other high power settings for long periods of time.

[99yam40]

but coming up slowly means they would be plowing for a little while with the nose sticking up in the air.
need to jump up on plane if you got a big a$$ motor (or motors) on the back

[TownsendsFJR1300]

but coming up slowly means they would be plowing for a little while with the nose sticking up in the air.
need to jump up on plane if you got a big a$$ motor (or motors) on the back

My boat would get on plane in 3-4 seconds if nailed easily. And that's a F150 on a 20'4" CC.

Since the balancer issues, I'm a little slower getting on plane, maybe 5 seconds and that's not full throttle..