Need Viper advice

[ViperMan]

Hey guys!
Hope everyone's enjoying their summer, out on their boats and such...
Anyways, I've got my viper, lower end was just rebuilt, and motor was looked at, so I'm not worried about that
BUT, after the motor work, I took the jackplate taken off, it was a 6 inch, and I was told for a viper that's too much.
So I went to drive the boat, and the engine is running better then ever, but my setup is wrong.
My top speed has dropped,
More of the boat is in the water then before, even trimmed up.
My top speed used to be 55mph ( but it chine walked)
I put the fin on it = 48mph
Removed jack plate =44mph


So what I'm asking from you experts!
What is it I need to do to get my viper rippin better than ever! But still drivable( without chine walk, porposing)
Because I know it should/can go faster

Prop is a 23p
Motor is a 115hp mercruiser
Please, any info is helpful, I've been struggling getting this boat setup for a while now, and getting somewhat frustrated.
Thanks again

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[ViperMan]

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[Surface Scratcher]

Don't be frustrated, working on the set up is half the fun.

It would help to have more info... where is the prop shaft in relation to the pad, what are your rpms, what type of prop?

Could your gear ratio have been changed when the lower unit was rebuilt?

Meanwhile, here's a page that will discuss a lot of Viper set ups http://hydrostream.org/TechTalk/TechTalk.htm

[ViperMan]

Thanks for the reply!
Prop shaft is about 3 inches below the pad.
Rpms- not sure because gauge just stopped working
Prop is a 23p, 3 blade stainless
And no, I don't think gear ratio was changed.
Thanks for the link, I'll check it out

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[Hippie459MN]

Thanks for the reply!
Prop shaft is about 3 inches below the pad.

WOAH!!! Get that motor WAY up. 3 inches below the pad will make that boat handle like poo. Get it up to at least in inch below, and assuming you do not have a low water pick up on that, raise it up until you just start to loose water pressure. You will notice a HUGE difference in the way the boat will behave.

I hate to be the one to ask but has the core (not the floor) ever been replaced in it?

[ViperMan]

Hey Hippie459MN
thanks for the helpful info, i figured this is a large part of the issues im having. Do you think i should get a 2" - 4" jack plate?
And im honestly not sure if the core was replaced, i assume not, because the previous owner didn't mention anything. Is there an easy way to tell if its had work on?
Thanks again

[aaron78viper]

whoa there, don't jack the motor up just yet, you need to make sure that thing has cooling water to the motor. you can only run the propshaft even with the pad if you have a low water pickup. Do you have a lwp?

[carson]

Get some dual steering on that baby to. These boat need to be driven, when they start getting up on the pad you need to keep it balanced or it will chine walk. Sloppy steering and rubber mounts will also make it hard to control. My valero is fairly easy to keep on the pad but if you dont keep up on the steering it will start to flop around lol

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[transomstand]

What year is the motor?