05' 353 w/600sci's drive height or props????
 

Need some input on what might be causing this boat to porpoise and wag its tail. Coming out of the hole it will crush the rev limiters just before the nose comes down if you let it. After the boat planes out ease the throttles full open and start up with the trim the boat will start to porpoise, running 85 @ 5000 rpm, bump the drives down it stops, bump them back up it starts again along with a tail wag, bump up a little more and feel the rear-end bite the ride gets sweeeet and it takes off to a little over 90mph and climbing when it slams the rev limiters again. Running a Maximus 30p w/boxes. I'm thinking maybe larger wheels for more bite will hopefully remedy the problem but drive height may ultimately be the culprit, or both. :(
Robert have you experienced any of this in your boat??

I will try to post some pictures, but that did not turn out very well last time.

Re: 05' 353 w/600sci's drive height or props????
 

I have done the prop slip calculations and they are 10% and 11%. Hope these pics turn out.

Re: 05' 353 w/600sci's drive height or props????
 

One more pic and I thought that I may add that there was no tab input at all

Re: 05' 353 w/600sci's drive height or props????
 

I'm on it. Let me make a phone call. Robert

Re: 05' 353 w/600sci's drive height or props????
 

Formula is going to drop ship a set of 31's made from 32's to your MS address. I will PM you to make sure that's the right address.Robert

Re: 05' 353 w/600sci's drive height or props????
 

That's hard to top! Great job Robert and Thunderbird!!!! :drink:

Re: 05' 353 w/600sci's drive height or props????
 

Is there a possibility you are just overtrimming? I found a tendency to do this when I moved up to my 382 with extexsion boxes. They are much more sensitive to trim input than non-boxed boats. What numbers on the indicator when you feel the problem?


Those props look HUGE already!

Re: 05' 353 w/600sci's drive height or props????
 

I just came out of a 353 w/boxes so I am familiar with the attitude of this boat. Only difference is 100hp more per side. If I was over trimming the boat would never bite and would instead start cavitating severely or the nose would lay-down and it would look as if I were running surface drives.
The boat is just starting to free-up when it starts to porpoise. The props are definitely loosing grip and not wanting to tote the nose of the boat, I am just not sure if it is props or drive height but it sounds like Formula and Robert have a good idea that the props are the culprit. I will let everyone know how the larger props perform.

Robert, Thank you

Re: 05' 353 w/600sci's drive height or props????
 

Hope you weren't offended by my suggestion. Just didn't know your level of experience with boxes.

Will be interesting to see if re-propping solves the problem.

Re: 05' 353 w/600sci's drive height or props????