Sea Ray

I had the same problem on a 21 foot. There are several ways to achieve results. 1. Lower pitch. Eg. If u r at 19 go to 17. If max rpm on an I/O is around 4600 rpm, leave pitch same go from aluminum to stainless as option 2. 3rd. Add a trim fin to the outdrive

I have a 2000 210 with a 5.0l 220 hp. Alpha 1 drive. 1.68 gearing. Boat came with an 3 blade aluminum 14.25 inch by 21 pitch. Engine runs at 4800 rpm. 55 mph. Plans at 27 mph empty. 33 mph loaded. I put an aluminum 4 blade 14 inch by 20 pitch. Plans at 25 mph empty 28 mph loaded. Lost alot of top speed when boat is empty. I can not trim the outdrive. Prop air rates. Rpm hits rev limiter. Loaded 50 mph.

Different boat (185 SP) but same issue. Did a lot of research and this is what I've done over this winter. First, swapped out the stock 23p aluminum prop with a 21p stainless. Also, added "Smart Tabs" as many folks with the same boat said they provided amazingly improved performance getting on plan with very little sacrifice at top end and at a small economic cost. Haven't launched yet this season but I'm optimistic.

You have several things to consider, engine's top speed (4800-5500 rpm full throttle ??), each pitch number increase lowers the rpms about 200, horse power and torque limitations, cupping of the prop blades, aluminum vs stainless prop (deflection), slotted hub prop, install trim tabs (8-12 inch), how much money that you want to spend.

Agree with all Raymond said. You can actually have your Prop "Tuned" at a Prop Shop as well. I drove for Mercury Racing a number of Years and Props can be adjusted by adding or taking out "Cup" and actually raise the Bow or Stern at RPM. In the case of Shawncayer, he's now "under propped" as he's hitting his rev limiter and cavitating which results in "cavitation burn", the technical terms for Blade Erosion. The diameter of the Prop or "Wheel" as refered to in some circles, can make a huge difference as well since most Props can only be obtained in Two pitch size incrementally. The max diameter is predicated on cavitation plate clearance from the centerline of the Prop Shaft. A more rigid material like the most common Stainless Steel is going to get you more power due to less flexing. There are also considerations for 3 or 4 blades plus pitch, plus diameter. In closing you can obtain the "Sweet Spot" by using the same pitch and changing diameter if you are in between pitch to achieve your personal desirable result. In any case you should be within 200-500 RPM of your WOT range. Hope this helps, fair Winds and following Seas!

Previous Sea Ray was 200 bow rider w/235 HP Mercruiser V8 and Alpha I stern drive w/ similar problem. Changed to 21p stiletto stainless propeller and dolphin tail. Trim tabs in lieu of dolphin tail also an option - albeit more expensive. Try the prop change first - I was surprised how much the aluminum flexed compared to the stainless coming out of the hole. You'll also get more top end speed, less cavitation during hard turns and more fuel efficiency for a given rpm. Then try the dolphin tail before investing in trim tabs. Be mindful of changing the propeller pitch - recommend checking with Sea Ray / Engine Manufacturer first. Good Luck!

From a safety perspective, please keep in mind that if a submerged object is struck by a stainless steel propeller vs. a softer aluminum propeller, more force will be directly transferred to the drive shaft / transmission.

Everyone,
Thanks for the suggestions. 99.9% of he time I'm running in fresh water. Is it the felx in the ss prop that makes the difference along with the pitch? I though that stainless would be a good way to go if I were in salt water. but not necessary in fresh.
What's a dolphin tail?
All the best and a great season to all Northeastern boaters.

We only used our 200 BR in freshwater.
The rigidity of stainless vs the aluminum makes a significant difference regardless of salt/fresh water and, for my boat, provided the primary benefit, the pitch change was relatively minor and provided a secondary benefit.
A dolphin tail attaches to your outdrive/lower unit and acts as a wing to provide "lift" during accelaration.

Charles, before you invest in a Dolphin Tail you might want to research Smart Tabs, too. After doing a lot of research I installed Smart Tabs and removed the Dolphin Tail on our 185 SP this winter. Haven't launched yet but if my results match tjose reports from other owners of similar vessels I'll be very pleased.