X19 PORPOISING PROBLEM

[BBW]

some of you may have seen some of my post about this boat , my problem is when running slow rmps less than 4000 with trim all way down the boat will porpoise, it is worse when i have two people in it i have tried a yamaha sho prop and a bravo 1 four blade it is better with the bravo, i have set ptp from 5 inches to 3.5 inches it does not porpoise as bad set deeper but does not handle as well on top end i talked to 2 different dealers one told me that sometimes they had to add welds to transom, i really don't like the idea of having to add welds to a new boat to make it handle, i wonder what that will do to top end performance, any help would be Appreciated, any one else had this problem

[alli ss]

At 4000rpm you shouldnt be trimmed all the way down. The whole boat is stuck but trying to lift. Trim according to speed and load

[BBW]

i cant trim any without porpoising unless i am over 4000 rmps

[Nickl]

i cant trim any without porpoising unless i am over 4000 rmps

I have no problems at all proposing .I can run 32 to 37 mph trimmed all the way up .Prop and set up is a must

[Nickl]

23 tempest plus .Prop to pad 3.5” . Sent the prop to Mark Croxton for balance and blueprint.Adds cup to the prop which gives the boat great lift .

[alli ss]

Start trimming as soon as the bow breaks over. Keep it unstuck and balanced on the pad. If water is spraying out the side at the console or farther forward youre still too stuck

[BBW]

alli ss i can run up to 3000 trim down after 3000 it bounces bad without trim if i try to trim it is worse, the only way that i can take off without porpoising is to leave it burried in water wot until i reach 4000 then start trim to get on pad i have tried 2 props that were recommended by xpress and dealer , the boat will not run from 3000 to 4000 without porpoising except wot and trimed all way down , i ran again this morning bravo 1 23 pt 3.5 ptp it ran 58 mph top side full tank gas 2 talons and 400 lbs me and my brother, and fishing gear. this is what xpress sent to my dealer001.JPG

[JR21RDC]

What jack plate you have. Also what motor and size pitch prop. Porpoising is the boat wanting to go up then losing its ability to hold the front up. Probably a prop issue. And or motor height adjustment. On some boats they mount a bigger plate on the cavitation to hold the boat up and divert water to the prop for more lift.

[ThomasD]

alli ss i can run up to 3000 trim down after 3000 it bounces bad without trim if i try to trim it is worse, the only way that i can take off without porpoising is to leave it burried in water wot until i reach 4000 then start trim to get on pad i have tried 2 props that were recommended by xpress and dealer , the boat will not run from 3000 to 4000 without porpoising except wot and trimed all way down , i ran again this morning bravo 1 23 pt 3.5 ptp it ran 58 mph top side full tank gas 2 talons and 400 lbs me and my brother, and fishing gear. this is what xpress sent to my dealer001.JPG

I see you mentioned a pair of Talons in this post but not original post. The added weight of them is contributing to the porpoising at slower speeds

[BBW]

i think you are right about weight my brother can move to front seat and it will not porpoise ,only problem i cant move anything more forward than what it is now ,just looking at the picture xpress sent it may not effect top end with those welds as far up away from pad, i don't know any other thing else to try

[roadkillIL]

In post #7, you said you tried 2 other props recommended by Xpress and dealer. What were the 2 props you tried, but did not solve your issue?
What motor do you have on your X19?

[BBW]

yamaha sho 22 pt and bravo 1 23 pt sorry i did not answer you have not been on line lately

[Nickl]

yamaha sho 22 pt and bravo 1 23 pt sorry i did not answer you have not been on line lately

I know every one tells you something different.Call Mark Croxton .You can waste a lot of time and money.Trying props.He knows props

[kondan]

Those welds are trim tabs, but you can try a CB foil/whale tail on the lower unit What hp motor?

[gr8basser]

Regarding those welds that Xpress recommends. You need them on many of these newer hulls(X19-X21). Trust me. Some boats have the welds already on them, but mine did not and it porpoised at low speeds and at 65-75 mph, worst in calm water....with a 26 Bravo 1 XS. To correct BOTH issues I did one thing... instead of welding in those locations, I used a $6 metal epoxy like JB Weld and formed a 1/4" thick bead across those areas in the drawing about 6" long each side. After it cured, I used a dremel and sanded down to apprx 3/16" thick wedge. The beauty of the epoxy is if you dont like it or it dont work, then tap it with a hammer and it falls off. When you want it on permanently, scuff up the paint and apply the epoxy. Handles great now, no porpoising unless I make it do it(you still have to know how to drive an Xpress), I am running about 2" PTP too. BTW, I did this on my X19 too(had that for 17 years). Hope this helps!

[roadkillIL]

No worries, BBW. Do u have the Yamaha sho 175 motor on your X19?

[BBW]

yep 175 sho, I talked to gregg at rothwell marine last week he sales and fishes from a x21 he told me that out of the three 21's he has owned one had no problems with porpoising one had to have welds and the new one he has now has a little not bad he said they get one ever so often that needs more weld beads and that would fix it. i am taking mine to dealer next week they have someone that can do the welds i will let everyone know how it works thanks to all that have give me help on this site

[BBW]

well i have to wait on boat repair found out this week , my wife has covid 19 , we are quarantined for 10 days that is if she doesn't get any worse. please keep us in your prayers

[roadkillIL]

Get well quick! Had to do the Q 14 day thing. nothing happened.

[bassm1n]

The advice to add a weld is the only real solution. I chased a solution via props etc and nothing helped.