Does anyone have this problem with their ZX250

[scbass]

I have an 06 zx250 w250 yammie. 27 t1 prop. When turning to the right at speed of 30 to 45 or so the boat porpoises real bad unless I trim it way down. When turning to the left it does not do it. If I have it up on the pad at higher speeds it wont do it. It will do it no matter how I load it or with 2 people or 1. This is my first skeeter and it seems a little weird that it does this. I love the boat otherwise. I fish a river that has a lot of curves and It is aggrivating to have to trim all the way down to turn.
Thanks,
Gary

[K.D.]

If I start off from a dead stop, I can run my ZX250 at 35 and barely touch the trim. If you're having to trim down to eliminate the porpoising, you've probably got it trimmed too high. They are very trim sensitive and porpoising is caused by a wrong combination of trim and speed. You either have to trim down or speed up to eliminate it.

You should be able to run as many zigs and zags as you need to at about 1/8th trim and 30-35 mph. This is assuming the boat is set up correctly. Do you know your prop height? I'm at 2.75" below pad on mine. Slow speed manuevering is something Skeeters are good at, but like I mentioned, they are very trim sensitive.

The other issue could be load distribution. Are you filling both tanks and have the selector set to "both" so it pulls from both tanks? Is your tackle in the center of the boat, with light stuff like PFD's and nets on the drivers side? (you have to offset the drivers weight)

List a little more details about how you've got the boat set up and maybe we can point you in the right direction.

[K.D.]

Take a look at this. You might gather a little info from the angle this boat is running at. They have very little, if any trim involved. This video is from Skeeter's website.

http://www.skeeterboats.com/ht....html

[scbass]

you are correct, very trim sensitive. I noticed that out of the hole you dont need to trim untill you get going good otherwise it will porpoise bad. My prop shaft is 2 3/4 below the pad and I am running a 27 t1 prop. I have life jackets, rain suit, throwable, cull e rite, drift sock etc in very front locker. 12 boxs full of tackle in 2nd front locker. 12 rods in left locker and first aid kit, flares, snack box, toilet paper, bug spray, paddle, lure retriever, small bag of tools, etc in right front locker. left rear has anchor and rope. right rear has boxs of light lures like top water baits bussbaits, spooks, jerk biats etc. rear of boat has 4 batterys, 4 bank charger, oil tank and jumper cables. my boat will gps 70 to 71 with full fuel, livewells full, 2 people with there tackle. It is a little slow out of the hole with this weight and will porpoise bad when slowing down unless I trim way down. unlike the skeeter commercial it will take on a lot of water over the transom if you get off of it too quick. I bet the commercial dont have 4 batterys, full oil tank and 50 gal of fuel. I came over to skeeter from a stratos and dont get me wrong I love the skeeter it will take some getting use to driving it. I love it in rough water. Like I said it will porpoise only in a right turn with or with out 2 people or how you load it. I was thinging about getting a 25t1 and trying that. What kind of rpms and speed you guys getting with it. Mine turns 5500 with the 27t1.
Thanks,
Gary

[scbass]

I forgot to mention I run my tanks to pull from both but it always pulls more out of the left tank.
gary

[K.D.]

Your info sounds dead on to me based on what I've experienced with mine. Your boat and load info sounds almost identical to mine, right down to the location of the hand tools. I tried the 25T-1 and didn't like it. I lost some speed also. The 25T-1 works well with heavier hulled boats combined with the 250HPDI. The Champ 206 almost requires the 25. It won't turn a 27. My loaded speeds are also the same as what you described.

The deal with the tanks is standard and I don't personally know of anyone who has one that doesn't do that.

It really sounds to me like you'll just have to get used to the trim sensitivity issue.
I can slow down from a full speed run to an idle without ever porpoising. Just have to start trimming it down and as the nose drops, slowly take your foot off the gas. I put my finger on the trim and hold it there while it's coming off plane. You should be able to continue that and set it down without it ever porpoising. I tried out for the Skeeter Demo Team last year and that was one of the things they had us demonstrate during the try outs. They want you to be able to make a full speed run back to the staging area and set it down smoothly, with no bouncing or porpoising.

The backwash is kind of exaggerated when you've got the tanks and wells full and someone in the passenger seat. I'll bump the throttle when coming off plane just to avoid it. I rarely have it happen because I usually come off plane slowly rather than just taking my foot out of it.

If you're porpoising on take off, it sounds like you're taking off without putting your foot to the floor. By putting your foot to the floor the boat is in an acceleration mode and the porpoising won't happen if you trim it slowly. The guys I've ridden with that have porposing issues on take off are trying to take off at about 1/2 throttle and are trimming it up too high/too fast. Put your foot into it until you're at the speed you want, then adjust throttle.

None of this is meant as the gospel as I'm having to guess based on what you wrote. If you can't get it resolved soon, I'm sure a local Team Member would be willing to help you out.


Modified by K.D. at 9:53 AM 6/28/2006

[K.D.]

oh yeah...how many hours are on your rig? Mine only ran to about 5500 when I first got it, and after break in and about 20 hours it started running at about 5800.

[Marc Marcantonio]

I ran a ZX250 last year, and a 20 iClass now. Both boats are very heavy, particularly with a 250 hp Yammie. Both boats will porpoise at slow speed as a result unless you trim in the engine.

This is something that you should expect and is easily compensated when you get used to dealing with it. I usually anticipate needing to slow down from higher speeds by first starting to trim down with my blinker trim even before letting up on the throttle. Since the Yammie has a large trim range, and is fairly slow in going from one end of the trim range to the other, I start trimming early. You also gain better boat steering control and speed control by trimming down whenever you slow down, and you minimize prop wash upon stopping.

I can drive my boat all day and never porpoise...but everytime my partner drives it we porpoise because he just isn't used to trimming down appropriately with his speed.

When running at around half speed, I use about half trim...at the slowest planing speeds I trim all the way in. The only time I'm trimmed all the way out is when running flat out (actually I'm trimmed out all the way, and then bump the trim back in just a little to get top speed).

It would be unreasonable to expect any high performance bassboat to not porpoise at slower speeds without trimming down first. Once you get the timing down, it becomes simple and smooth.

[scbass]

sounds like everyones zx250 handles like mine. I am satified with that. It will just take some use to and trimming it will come automatic. KD I have about 50 hours on mine now and it only turns 5500. Most of the time I have 2 people with me. We fish tournaments every Thurs and Sat evenings and an all day tour on Sundays. I will try to get out this week by my self and play with it. Looks like my rooster tail is a bit higher than the cowling. I may lower engine down 1/4 of an inch.
Thanks so much for the help,
Gary

[gho4950]

I really don't have the porpoising problem but I agree it is related to the trim and timing of its use. After time it becomes second nature. I load my boat pretty well, I'm a you never know might need it. Loaded with 2 people and gear, full livewells and 1/2 to 3/4 gas I can turn 72 - 73 at about 5600 rpms. It actually drives better with 2 people, alone it will walk if I don't pay attention and I still dont think I've got all I can. I also run the 27TI prop.

[bayoubeagler]

I think the video just pulls the kill switch, its not pulling the throttle back.