Iīve just come back from ten days on the water taking part in the "Liquid Quarter Mile" event that a bunch of us compete in every Autumn. I ran my labbed 26" Maximus (to get the best acceleration) and was seeing 77 mph GPS @ 5350 before the revlimiter would cut in. My issue is that I had a couple of "moments" that really shook me up, and has convinced me that I have got to change the settup.
Once running in a strong and difficult crosswind in big chop at 70 mph, but also once on a long 2" swell on glassy smooth water at 76 mph, I found myself fighting a chinewalk that very nearly had the boat at 45° in both directions, several cycles, and sriously scared me. In both cases it built up real quick, and with little warning.
The short five blade didnīt help, but I feel that I have to drop the drive (2 1/2" prop to pad, on a 12" exrtension) to get back the solid handling that I had with the 525/stock XR settup.

My best time on the LQM was a 16.79 time, but was beaten by my buddies in a 662 powered Activator, a blown 515 in a 28 Pantera raceboat and by a procharged H2X! We had great fun, and didnīt blow a drive!

Try installing a 1" drive spacer.

Stephen, sounds odd because you've had the boat in the upper 70's and low 80's a thousand times. Is your steering loose or something else awry?
Mine chines a little bit if I'm trimmed up but can always (so far) keep it under control by working the wheel.

Did you try a little tab on it ?

My boat runs the best with the tabs just slightly
negative.

Has it only done it only with the 26 Maximus prop? Different props, as you know, can really change the handling. What do you normally run?




Darrell.

When I tried the 28 pitch maximus (with the ext box) on my baja it torque rolled to passenger side terrible. I'm sure the 5 blade is probably the culprit for your chine walk as it can climb up on the water and throw you around. You already know this but most likely when you go back to the 4 blade with your C/L so high it will probably slip too much so you'll need to experiment with spacers. Have you had any problems with prop blowout? I just went to a -2 shorty and my prop blows out if you trim it more then 1/4 way of total trim at high speed. When it does this the bow drops suddenly and boat bow steers awful,Smitty

Yes, it sort of surprised me, too, after all the seat time Iīve done in this boat. The 26" Maximus is certainly making things worse, but the basic problem started with the high x.

No, the steering and drive has absolutely no slack, and after all the hard running hours really speaks for full. twin ram hydraulic steering!

I had notice (when running the 28" and 29" Maximusīs) and crossing other boat wakes that the boat would dig itīs nose in as it landed, causing a chinewalk-like dance until the hull settled and gained itīs balance. This would always sort itself out and I didnīt need to back off.

On the two occasions I described above, there was no chance the boat was going to settle, and steering inputs to break the rythm (usually works) just amplified the swing. A few second off the throttle settled things, but it just ainīt how it should be.
Iīm going to drop the drive another inch (2" spacer) and try some of the 4 blades.

Prop blowout? Well, when Iīm cruising at say 40 mph trimmed level, no tab, the boat will porpoise very gently and the revs climb and drop as the prop loses a lttle grip. However, once I put on the power the prop digs in and goes a little deeper and the thereīs no real problem there.

2 1/2" prop to pad depth does appear to be a lttle too much of a good thing, and quite possibly the reason for the handling issues.
Like I said, I was throwing the boat at every wave i could find last year(with a less torquey 525) and did not have this problem.

One inch might make the world of difference, here!

I run maximus's on my boat.

A couple of weeks ago I tried a set of
Precision propellers ( the people that make
the "turbo" 3 blades) new 5 blades.

While they were not quite as fast, ( they
were box stock, my maxes aren't)
the boat seemed much more at ease.

Brett @ Bblades carrys them, he has a demo
program..being that they're new, I don't know
what sizes he has in stock, but, they might be worth
a try.

I know a couple of guys on here have also tried them
and have commented positively about them.

Thatīs my plan. The Maximus props (that I was sooo enthusiastic about a few months back) just donīt suit my settup. Iīm looking forward to getting back to the solid handling of the four blade, but want to reduce slip somewhat.
Iīll be looking at alternative five blades.
Dropping the drive an inch (from 2 1/2" down to 3 1/2" below pad) will help, as well.

hope all is well, are you still on here stephen?