Hooked Hull??

[go phish]

So, My new to me 2011 z7 runs 49 mph @ 4900 rpm wot with a 24p tempest plus, motor is on the 3rd hole from top and my bpd is 3 1/2", no jackplate...Just me,
( 225 lbs) standard gear, nothing heavy up front..According to the Mercury prop selection a 21p is recommended to increase rpm to 5500 and speed to 59-60 mph. Got a great deal on a new Tempest 22p so figured that would get me the top end of 55-56.. Not too bad I'm thinking..Well now it does 5500 rpm with the 22p but top speed is 50 mph..I was talking to a local Mercury mechanic and he says that model year of Z7 had problems with hooked hulls and mine probably is hooked...and that's the best I'll ever get out of it...? I'm not giving up so easy. Will a jackplate get me there? Dropping the motor to the second hole? Mechanic says he's seen this before and nothing will change it.....Any ideas????

[BMCD]

Well get it checked before u spend anymore money.

[Fishysam]

How much trim/ rooster tail? Just for reference my z8 250proxs won't break 48 mph if I don't trim out, then it pushes up to 76+ when I push it all the way up

[5dinkbass]

Are you porpoising at all at higher speed?

[OldTimer57]

take a 6' straight edge and hold it against the pad. There should be no gap between the hull and straight edge anywhere. If there is a gap in the center, you have a hook. If the gap is on either end, you have a rocker. A rocker will cause porpoising at higher speeds. A hook will cause significant drag at higher speeds. Neither is good. Either ought to be handled by a lifetime warranty, as either is a definite "manufacturing defect". Often caused by popping the hull out of the mold too soon and then setting it on a dolly where the supporting point is at the middle of the pad and the hull "sags" since it has not yet finished curing. I don't know what nitro does with the hull warranty once a boat's title is transferred to a second (or third) owner. Bass Cat supports the lifetime warranty so long as the warranty is properly transferred when the boat is sold, no matter how many owners nor how many years since it was built.

[joebone1]

i took a hook out of my 1988 stratos - the actual problem was on the lip of the pad. i didn't have to take much off - probably less than 1/8 inch.

[go phish]

Trimmed all the way up, rooster tail off to the right some about 3-4 ' above the motor..

How much trim/ rooster tail? Just for reference my z8 250proxs won't break 48 mph if I don't trim out, then it pushes up to 76+ when I push it all the way up

[go phish]

No bow lift, no porpoising...

Are you porpoising at all at higher speed?

[Fishysam]

All this is a new boat to you? Or has it been getting worse?

[remaly181]

First, 23p Tempest is the way to go with that 150. Secondly, I would start by raising the motor instead of burying it any deeper. And to answer your question, yes, a jack plate with make dialing that thing in sooooo easy.

Also, I've known quite a few people with 2011 Z7s and none have had a hook like some of the later Champions. But, it never hurts to check the pad quick. Mechanics like to throw obscure crap out there to impress you when in reality it is just something simple like the right prop at the right height.

[grayline]

Yup remaly is correct... my Z7 has a PTP at 3" I turn a 23 tempest tweaked by mark croxton to a cupped 22
I have a 10" jackplate my motor is 2nd from the top i think a 24 is too much pitch .goto your local marina and borrow a 23 and see what difference it makes

[Brewerbass]

Original post said he has tried a 22p and still not making speed. Something isnt right with his set up. You dont have any water in the boat do you?

[Fishysam]

Primer bulb on fuel line hard and stay hard? Maybe crack the gas cap on a nice day and run it? If either of these don't work maybe a pinched fuel line under the cowl? Bad plugs? Carboned up motor? Optimax? Bad compressor?

[squarebilljunkie]

There was not a 'problem year" for Z7's and hooked pads. Check it anyway, a hook can happen on any model of any brand. Sounds more about engine height and prop than anything else. Also pay attention to total weight in boat and how it is distributed.

[go phish]

No.. No water..

Original post said he has tried a 22p and still not making speed. Something isnt right with his set up. You dont have any water in the boat do you?

[go phish]

Just had the motor checked out..All good. Motor runs good..

Primer bulb on fuel line hard and stay hard? Maybe crack the gas cap on a nice day and run it? If either of these don't work maybe a pinched fuel line under the cowl? Bad plugs? Carboned up motor? Optimax? Bad compressor?

[go phish]

I have a new 22p tempest on there now.. Boat jumps up and wants to go, but no top speed at wot over 50. Should I raise or lower the motor 1 notch?

There was not a 'problem year" for Z7's and hooked pads. Check it anyway, a hook can happen on any model of any brand. Sounds more about engine height and prop than anything else. Also pay attention to total weight in boat and how it is distributed.

[Brewerbass]

Are you measuring gps speed or just the guages?
There was someone else had similar issues and it was a problem with his trim that when fixed cured it

[remaly181]

What is your psi at WOT?

[go phish]

GPS Speed.

Are you measuring gps speed or just the guages?
There was someone else had similar issues and it was a problem with his trim that when fixed cured it