33ZX getting up on plane
 

I purchased a '04 Donzi 33' ZX last October and we are having issues getting up on plane. I bought two out of the box new 26P Mercury props and had the boat out yesterday for the first time this year. I use the slow and steady approach when starting out of the hole. I keep the trim tabs up and when throttling up I start to put the trim tabs down when the boat seems to get to a point where it needs help over the hump. It gets up to about 3600 RPMs before it starts trying to plane out. If I give too much throttle it will blow out the props. It just seems like the boat is sooo heavy to get up on plane.
Can anyone with a similar boat tell me if the are having the same issue and if there is anything different I can do to get up on plane quicker?

Make sure your tucking the drives. I can't go much over 3k before blowing out but she walks right up, just can't go heavy on the sticks... Which is good for the drives too I guess. My is a lil different as I have str8 bottom, but your steps might require some tabs. Also try using tabs before trying to get on plane.

not the first time I heard this about an 04 33x. I think Donzi got aggressive with the x dim on the boat. Put tabs down to 6-7, drive full in, throttle to 3500, keep engines rpm from blowing props, lift tabs to 2-3 after boat rolls on plane.

I have the same boat but a 2000. I have the 500 efi's and spinning 4 blade 28's and I dont have a problem. I start off slow and then roll on kinda quick the boat seams to lime it.

I have drives tucked and tabs at about 2. Here is a video how mine comes up and out.
http://youtu.be/20HPZ9fhoaQ

Even my 28 is like that with factory props. I go tabs down throttle up then start pulling the tabs up as it starts moving. It's a PITA and really hard when you are planing in rough water. Because I don't use the boat for top end a lot I swapped props. For me that meant going from 3 to 4 blades. I'd think for you a set of Maximus props might be the trick.

Bury the tabs, and drives fully tucked in. You may try to rock it back and forth with the wheel which can help some boats.

There is a technique used on some race boats where you wait until it JUST blows out, and then yank the throttles back. Let the wall of water hit the back of the boat, and push the boat forward, and simultaneously push the sticks forward so the props also bite in that wall of water that is lifting up the boat up. Hopefully, you do not have to do this.

My 33zx doesn't plane quick as say a 33outlaw but it isn't all that bad. I also have the 500 efi's 2003, don't seem to remember ever worrying about blow out. I've got 26p bravo ones (4 blades). It does take some rpms to push the boat over though.

Oh quick thought, what position are your celery sticks on the trim cylinders. I forget but one position over the other tucks the drive further under. They call it the trim limit insert.

My buddys 28 ZX blows out the props as he pull it up on plane and m 34 baja does that too if you hammer the sticks, but it also like a little slip out of the hole.

I push mine till they blow a little and keep them around 3500 as the boat pull sup and out and hooks up.

I remember that being an issue with the 04 33zx on our dock.

I have been walking the sticks up really slow....maybe a bit too slow...

My 38 ZX has 26p 5 blades and I run the sticks up to 3k. I try to keep it right there until it gets over the hump, it's not fast but seems to do the trick every time. My tabs are up and drives are down. Soon as I'm on plane I give a little trim and I'm running over 40 at just over 3000 rpms.

sometime i find it easier to do full tabs down and trim tucked in all the way, i can get up in shallow water

sounds like you have 2 = = =3 blade props,,if so get rid of them and put a set of bravo pnes r rev 4 blades on it..

I have a question, I know different boat but I always have drives in all the way and tabs all the way down to come on plane, why would you NOT put both in/down?

As it rolls over I bring tabs up first then drives and adjust from there.

I just dont use my tabs casue the boat comes up with out them easy and I am lazy do i dont have to work tab buttons and drives once its rocks. up. it takes longer to raise them back up then it does to get the boat on plane.

nothing wrong with it though I have done that some just testing, playing or what ever.


Not close up, but I forgot a buddy has a video of my boat taking off. you can hear it rev to 3000-3500 and i just hold it and it rolls on plan. tabs flat, drives all the way down.

https://www.youtube.com/watch?v=F5gjyaZy6rI

I would use tabs to get on plain if it was rough waters or shallow, the bow hangs out far enough on mine that I don't need them when it's calm out. To me they seem like you are making the boat work hard as your adding more drag. I find myself using them mainly to level the boat when I have a lot a gear on board or have a good stiff wind listing the boat.

Five blade is a must on a 33ZX in my opinion. I've run a few. I have a set of Hydromotive P5 - 30's that I need to sale that work great on a 33ZX. I ended up getting a larger diameter Merc Maximus that works better with my extended ITS / XR drives.

I had to be very gentle to get my lab'd 4 blade bravo's up on plane. The P5's don't blow out at all. The larger diam. Maximus takes a little gentler hand, but probably easier on the drives that way.

Also, you want to make sure you have a little forward momentum before getting into the throttle, as these aren't drag boats.

How did you make out with planning? Mine is still blowing out just as its rolling over, around 2500rpm mark. After that I'm throttling up to 4,000-4,200 rpm then it planes. Drives and tabs tucked in. Just hoping you found a solution. Running 28p but have tried 30 stock and 30 labed with same results.

Last year was our first season with the boat so we had a learning curve. I put new 26P 4blade bravos on and that did the trick. The previous owner must have hit something to the point where the blades were not per manufacture spec. I don't need tabs any more and do tuck the drives. I try to roll into the throttle pretty steady til I hit 3000 and it comes right out of the water. I also try to get a little momentum before getting into the throttle. All is good now thanks!

What rpm and speed r u seeing on the top end with the 26's?

About 72 to 73 is top speed at 5000 with 26P

And u have the 496's or 500efi's or 502's?

496 HO's

Mach, what is you measurement from prop shaft to bottom of your swim platform? I've measured a couple other 33's and my x dimension is much higher. Although the 33's where different years than mine.

I will be at my boat this weekend and will let u know

What # did u get on yours and others ?

On other 33zx models I find 41", mine us measured at 38". Prop shaft at level trim measured up to bottom of swim platform.

From tge bottom of the rub rail to center of prop shaft I got 48" with the drives in neutral position whisper my boat is on number 2 on the gauge. not all the way tucked in

If you are not demanding the best top speed then go to Bravo 4 blade props and You WILL be real happy with how it gets on plane. My 34 SCARAB used to be very problematic getting on plane. There is a video on here of it blowing out and me back pedaling.
I went to 4 blades and then you could pull up skiers. (used to do this on a regular basis ) I then went to -2 IMCO shorties and my planning was a little more eventful. I would just roll into the throttle and hold it at 5000 RPM and it would just push up onto plane in about 3 to 5 seconds.
My Daytona is a different story. With the prop shaft 1 inch ABOVE the bottom of the hull I have to do the same 5000 RPM but it takes 5 to 10 seconds to push over until it hooks up. I am actually going back 12 inches and up another inch before it goes on the water this summer. It is real easy for me to go down but as always very difficult to go up. I am running a -3 IMCO shorty now. I have a -2 IMCO lower also.

One big change I made was increasing the negative trim range of my drives. I shortened the trim rams 3/4 inch and with a little careful grinding ( in areas that DONT effect the strength of the gimbal ) I was able to get a lot more negative trim and that greatly improves the props ability to push the boat onto plane. Shortening the trim rams is a very easy job. Any engine shop should be able to do this. ( they do need a lathe with a 3 inch head. )

I'm running 28p bravo 4 blade props.

That is what I am spinning as well. Looking to have them labed next winter.

I tried a labbed set, no real performance difference, the 30 bravos lowered rpm touch but raised top end and had nice acceleration

My measurement to same points was 45, so a consistant 3". Higher than others

Thats a bit higher. Maybe u have shorter lowers I was thinking about geting shorties but someone told me save your money.

He sead the gain if any is not worth the coin. ....

Has anyone get a 33 ZX over the 92mph? Mine jumps right at 90 and i cant eliminate that, so you have to push back the throttles... Tried several props Maximus and 4 Baldes...

I have -2" Stelling Boxes with XR and -2 Sc Lower and my X Dimension is 4,5" right from the bottom of the boat (where the drive is) to the propshaft...

Has anyone experience with that or an idea?? Thanks for your help!

Have you tried to run it with the tabs around 3 at that speed? With the tabs around neutral or a little down that extends your running surface and stops the hopping.