Motor Set Back

[Chrisschuh1]

Hello,

I was wondering about how you determine what the set back should be on a boat.
I have a '90 Hydrostream Vassarette YT w/ 200 promax and Bobs nose cone.

Thanks

[panther150]

Bowrider" regular non bowrider would be 6" and bowriders usually went with 8". Every hull layup up is a little different , as is what you want to do with it. Great hull / motor combination

[Chrisschuh1]

Thanks! It is a bowrider and the current set back is about 8.250".
What about jack plate height?

[panther150]

setback sounds good, if it's a manual plate I would start with the prop shaft even with the bottom of the hull. Then try moving 1/4" up at a time . Make sure you have a water pressure guage.

[Chrisschuh1]

It is a Hydraulic Jake plate.

Motor is pretty built and compression is good, but with a 26p prop I can only get about 63/64mph before it starts walking around. I know its not the best prop (Laser II), but sure seems like it should be faster.

Thanks for the advise!

[flatbackcanoe]

A Vagas XT hull has a tricky spot around that speed where the tunnels start to lift out of the water to leave you running on the centre V pad.
On the YT hull, the bottom of the sponsons sit lower then the bottom of the V pad. Not sure what that would drive like, maybe similar.

Is it doing those speeds because the engine doesnt have anything left, or because the boat feels out of shape and you get off the throttle ?

Make sure the boat is in good shape, transom is solid, core/stringers are solid, no soaked foam.
Quicksilver Laser is a good propeller, they hold together when surfaced.
Engine RPM and intended use of the boat determines the propeller pitch.

That boat, with that engine, should go over 90 I'd think.

Prop shaft an inch below, go up or down from there.

[panther150]

sounds like your motor is too deep.

[David]

i used to have a Virage, similar bottom. No chine walking when the engine was high enough and it was faster the higher the engine was. Water pressure limited even with a low water pick up nose one.

But my Laser had lousy lift at high engine heights. A Hoss Hyperdrive worked a lot better for top end.