Joker Jake wrote: ↑Aug 18, 2023 7:26 pm I do not have a lwp or nose cone. The prop shaft centerline is about 5' below the pad. I experimented with it up about 2" from there and 1" down from there.
When I got it back on the trailer I tried to wiggle the motor side to side and found some slop (hydraulic steering). This seems like a possible problem. Probably not bled well enough when I rerigged the boat.
Mostly I have read about people with porposing issues. Is this side to side roll unussual?

It could be if your engine mounts are worn too.

Set back is the jack plate that bolts to the transom that you bolt the motor too. As for not having a cone on the lower, raise the motor up as high as you can without loosing water pressure. Blocking off the top one or two water intake holes on the lower can also help get it up higher without loosing water pressure. And get that steering tightened up and solid motor mounts will be your friend. No one said going fast was cheap or easy. lol

As you can see, my Vulture has a 10 inch plate on it. I might go to a 12 inch but not sure yet. These vultures LOVE the set back due to the cockpit being so far forward on them.

How do you measure setback? Thickness of the jackplate or distance from cone to pad or other?

I do not have a lwp or nose cone. The prop shaft centerline is about 5' below the pad. I experimented with it up about 2" from there and 1" down from there.
When I got it back on the trailer I tried to wiggle the motor side to side and found some slop (hydraulic steering). This seems like a possible problem. Probably not bled well enough when I rerigged the boat.
Mostly I have read about people with porposing issues. Is this side to side roll unussual?

The transom could be the reason. Whats your set up like? Set back, motor height (prop shaft to pad), nose cone with low water pickup?, etc....

I got the 27" pitch Tempest prop. It is allot faster. 60 mph with lots of throttle left.
Why only 60 ? Because I got scared. The boat starts gentle rolling side to side at that speed.
Is this likely a set-up issue, or do I need driving lessons? Anyone got some advice?
The boat has new core, stringers and floor.
The soft transom will get repaired this winter (the other reason I didn't push it).

I see a Mercury Tesmpest plus prop for sale in my area.
It is 14.625 X 27 pitch.
The current prop is 13.25 X 23 pitch.
Is this too much prop? The larger diameter concerns me.

Without a low water pick up you're going to be very limited on performance props. ET's, SRX's and choppers, all work great on a Viking but will need a low water pickup. I would look into a Trophy or Tempest probably around 26" pitch and run it as high as you can without loosing water pressure. This should get you well into the 70's if not over 80.

Every hull and set up is a bit different and requires testing, so you'll end up buying/selling lots of props. I went through 8-10 before finding exactly what the boat likes. If you're lucky some guys in your area will let you borrow some to run. Some dealers will allow you to take a prop and test it with a deposit.

Like said above it will depend on what you're looking to do with it. I have a few props laying around for different outings.

With all that said to get the most out of the boat you'll need a low water pick up to get the motor up higher. Under those circumstances my boat loves an ET.

Tony.

How the boat is used will determine the prop recommendation.

Family boat? By yourself just buzzing around? 4 bimbos pulled on a tube?

Your lower unit will limit how well a performance prop will run, ideally you want to surface a chopper on a V-King. Maybe look for a 26" laser 2, that might be a good compromise

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