Keeping boat on step
 

Here is the problem. I have a 91 Baja 290. Have tried several things to get the boat to ride better and get more of the hull out of water. Looking at pictures of boat running I have most of the bottom of boat in the water. I have a friend that has the identical boat and he has same issue. Is there something we are missing? Here are the facts:
91 Baja 290
29 ft OAL
9 ft beam
6500 lbs
38 inches draft
21 degree dead rise at transom
135 gal fuel cap
920 total HP (twin 454)
bravo mirage 3 blade 25 pitch props (turning out)
stock bravo 1 drives
stock cheap a** bennett tabs 16 inches long

Really like the boat for its room but just doesn't ride well. I do not carry any excess weight in boat and usually ride with 1/2 to 3/4 fuel in tank. Will only take a few bumps on the outdrive trim (less than quarter trim) before she starts to bounce. Hope some can shed some light.

My bet .... the 3-blades cannot hold the bow up, thus the "bounce".
Although this seems like a CG or X-dem problem, and sternlift is not really needed, the additional grip
of a 4-blade prop should provide a more stable and responsive ride. I know that they can also be cupped
to partially offset their sternlift tendancy. Call Julie @ ThrottleUp, I'll bet she can provide some great insight on your problem.

Does Julie have email or how do I get in touch? Also when the boat is under way the tops of the outdrives are still in the water. Is stern still riding too low? If I change props, do I go lower pitch? Have not had the boat on the stops yet cause of new motors, but the fastest I have had it so far is 60 at 4200-4300 rpm and a quarter throttle left.

Do you have a lot of "stuff" in the bow? My thought is make a run with everything out of the cabin area and try turning the props in to push the stern down. If the bounce gets less, it will send you in the right direction. Did the boat do this when new? Was the X dimension changed?

ThrottleUp is an advertiser on this website and you can get her contact data there.
I belive you are running stern heavy since the drive tops are submerged while underway.
No need for a drive shower I guess :rolleyes:

Assuming you have 5000rpm engines, I would test with 22p Bravo/1 which could be upgraded to 24p depending on results. Most good prop firms have a testing program available on stock Bravo/1 props.
Also, you might inquire about any benefit of changing the props to turn inward.

Also, don't do much until you get some good WOT running data to consider.

I have gave the boat a diet of sorts and removed alot of "stuff". What do I have to do to run the props "in" and what would this do to the handling of boat? As far as the engines they were dynoed at 5600 RPM but these engines started out as 330 hp. I'm figuring 5000 rpm to be safe.
I do not believe the x diminsion had been changed and yes the stern does sit and ride low in the water.
Thanks for all the insight.

Just switch the props and put in shifters in reverse to go foward. This is just a test to see of the bounce slows. Does the bounce happen at all speeds or just in the mid-range?

As soon as I get on plane and start to get the boat to loosen up. Anywhere from speeds of 30-60mph. If I do this "test" with the reversed props and it does help,what then?

Adding more blades will create more stern lift. You may actually need some stern lift. The entire boat will lift more out of the water.

Spinning the props inward will give you more bow lift, but will make docking more difficult.

Drop to a 24" Bravo 4 blade if your wot rpms are close to correct now.

Sorry I have been out of touch a days but yes I was thinking on going smaller with a 4 blade. Now if I can just find a decent deal on some used ones.....................
Thanks for everyones input.