porpoise
 

2004 37' Does any buddys boat porpoise at speeds at 55 any higher on flat water.Is this the nature of the boat.Trim the drive up alot goes away.

That does not sound common. The boats do not need much trim, which is a common mistake. Neutral to 3 "notches" (on the K-dial) above neutral is ideal.

I do know of another boat that was stored on a rack that was not fit for the step, which affected the bottom. It required a blueprint to fix it.

Mine and a couple more I know of do it on flat,sticky freshwater. The stock 32 bravo props don't create enough bow lift to correct it and are very easy to blow out trying to get on plane in those conditions. 28P labbed Maximus solved both problems.

What speeds are you getting with both props.My boat has 525s are those props to big.Running 30 lab bravo.Fully loaded only seeing 80-81. At 5100 rpm.

Which boat do you have? Is it this one? If so, who redid the bottom?

Yes that is my boat and my brother and I fixed the hole boat are self.So i know the bottom is straight.

Well she is a beauty. Are you coming down to lake Cumberland?

Yes i will be there. staying at state dock.comming down on thrusday

The issue with the porpoise has more to do with trim and buoyancy than any thing else. If the drives are tucked in flat fresh water, the boat can’t decide if it wants to ride on the pad or pivot on the step. The water is not buoyant enough to force it. So it teeters on the step. Trim it out and carry the bow and the boat will settle in on the pad. I am always trim out to at least 4 unless super rough (4+ footers) and then I will only trim it to 3-3.5). Never any lower.

On the side note, my boat has never porpoise but my boat is very different when it comes to COG and weight distrabution because it lacks a liner.

With regard to speed, the previous owner use to get 85 out of the boat with stock 30’s at 1000 feet in California. If you are only getting 80-81 then check altitude, bottom, and wheels. Did you truly blue print the bottom after you fixed it. Is every edge from two feet in front of the step back to the transom perfectly strait and extremely sharp?

Along with Mark, try a set of 28 labbed Maximus props. They are a good wheel for the boat.

I was waiting to see who knew the correct answer and it was Clarkstar!

Actually I drive every boat before delivery and the linered boats due in fact need the extra trim.

But like Mark said the Maximus 5 bladers also help and come out of the hole really nice.

I think what happens is that when you guys trim the boat to say 4 or 5ish and the boat rocks between step and pad, the natural reaction is tab it which then REALLY confuses the hell out of the boat.

As far as the speed Tom is getting, I think we all agree that the 30 Labbed prop isn't right for the boat but I would be curious if they are Merc Labs.

Was the damage in front of the step?