rdoactive

What Wobble said. Try a couple props with more or less cup. Some dealerships will have "loaner props" for you to try before buying. Also try a 4 blade. Do the simple stuff first

swaaby

Thankyou. I tried a 4 blade 22 pitch b1 and lost all my top end as a matter of fact I lost about 8mph, Man I was extremely bummed, the prop guy said he could cup it some more but really wasnt happy about that. With the 4 blade the boat did alot better it still hopped a little and came out of the like it was nobody business I called throttle up and they did not do the loaner program with 22 pitch props so again back to the old drawing board. thanks again guys

cosmic12

did you ck to see how much hook is there? I agree that most pleasuer boats have a little hook or rocker in the hull to make them user friendly.Having worked for a Baja dealer and driveing alot of them and seeing what they do to the bottoms it generaly inxs of what you want there for higher speed running. I have sean them be as much as over 2 inchs at the transom but only go forward 6 inchs . just my 2cts

ECeptor

When you lost your 8mph, did you lose rpm also? If your rpms were up near max, then you could try a 24p b1 to pick the speed back up.

ECeptor

swaaby, read this thread on the subject...good info in there.

Hydrolift

HOOK And ROCKER
The bottom is referred to having a ”hook” if it is concave in the fore-and-aft direction. A hook causes more lift on the bottom near the transom and forces the bow to drop. This increases wetted surface and reduces boat speed. A hook, however, aids in planing and reduces any porpoising (rhythmical bouncing) tendency. A slight hook is often built in by the manufacturer. A hook also can be caused by incorrect trailering or storing the boat with support directly under the transom.

The opposite of a hook is a Rocker. The bottom is convex or bulged in a fore-and-aft direction. It can cause a boat to porpoise.

This from Mercury Racing Manual.

jpclear

Now, Hydrolift has gotten to the point! "Hook" makes your boat plow, not porpoise. "Rocker" causes porpoise. The Mirage and Mirage+ props (what you run) are terrific "bow lifters", and that is NOT what you need. Try a known "stern lifting" prop (such as a Hydromotive O-IV) in your pitch range before messing with the hull. The folks at Throttle-Up can point you in the right direction if you can give them all the proper info. --- Jer

swaaby

ECeptor, If I remember right I think I was maxed on RPM's.

swaaby

jpclear, Thanks alot I will call them today with my specs again, The only thing is they do not have the prop program for a 22 pitch, However they said if I bought one they would exchange it for what I need. To me that is the same thing except you pay for it ?

ECeptor

Then try the 24p.