Mercury optimax 150hp top in speed

[sbhonch]

I have a ranger reata fish and ski with a merc optimax 150. I bought the boat brand new in sep 05.

The motor came factory with a 5 blade prop.


My top in speed with this set up is about 44 mph if im lucky.


This is my first boat so im not really familiar with the props and pitch and all that stuff.

Can anybody help me pick up some speed, or should i just go to a bass boat...

[mhall]

What length is your boat and weight if you know it?

[jdw174]

The Merc "Hi-five" prop is definitely NOT made for speed. It is, however, a good "pulling" prop. If you're mainly water skiing, that's the prop to use.

I'm not totally familiar with Merc props (I run OMC/Bomb), so using that brands Raker (3blade) and Renegade (4blade) as an example, the Raker is a bow-lifter and is the fastest prop. The Renegade will be quicker out of the hole, have less steering torque, and will be somewhat better in rough water. It lifts the stern of the boat quicker. It's not as fast as the Raker. I am assuming that the 3 and 4 blade props from Merc have the same characteristics. Performance from all props can be enhanced by having them reworked by a custom shop.

[BabyHeuy]

A general rule I have heard is you give up speed the more blades on the prop, but you can run on plane at slower speeds with more blades on the prop.

If you want speed. I would think a 3 blade Mercury Tempest would work well. Not 100% sure, but maybe around a 23 pitch prop.

I'm not an expert just talking from past experience.

You can look at bassboatcentral or bass fishing home page they have forums on props and performance


if you need the addresses of these sites
you can email me [email protected]

[sbhonch]

Thanks for all the info. My boat is 19ft. Not sure on the weight.
I think i will try a 3 blade prop and see what happens. I never pull skiers so having a 5 blade really does me no good. Im looking to go faster.

[BabyHeuy]

I can put you in contact with a Ranger dealer that would could help you. My email is [email protected]

I'm on the pro-staff at this place and they are second to none when it comes to the service department


Thanks,
Jason

[mhall]

I have a 14 inch 23 pitch three blader on a 18 foot fish and ski. The motor is a 150 v-maxx yamaha and the boat is a Champion. Champions are heavy, and I'm getting 62 mph out of that boat with me a full tank of gas and all my gear. However pulling tubes, skiers ect., it doesn't do that great which is something I very rarely do anyway. The advice about the props giving here by the others sounds dead on to me.

[CA]

I have a Procraft 180 combo fish and ski. This a heavy boat, the hull alone is 1650lbs. I run a 200 Optimax which weighs 528lbs. So I'm running a heavy rig. I run a 3 blader laser II 23 inch prop and still get around 65mph. I think you would gain a lot of spped with a three blade. Hope tihs helps.

[adam7456]

You top speed is going to depend on your RPMS, prop diameter, pitch, cupping, and number of blades.

To give you some more accurate information I need to know what your current RPMs run, the max RPM for your motor, the diameter of your current prop, and the pitch of your current prop.

Here are a couple general rules on props.

For each blade you add to a prop you can expect your RPMs to drop 150 to 200. Each blade you take away will increase your RPMs.

Similary going up in pitch 1" will reduce your RPMs by 150 to 200 and going down in pitch with increase your RPMs by 150 to 200.

Also a stainless steel prop does not flex as much as an aluminum prop so it gives a better bite. The general rule is if you have a stainless steel prop and go to an alumimum, your RPMs will increase the same as going down 1" in pitch. Going from aluminum up to stainless is like adding 1" in pitch to the prop.


Here is how it all plays together. I'll use some of your info in this example.

Let's say you have a 5 blade stainless steel prop at 26 pitch. If your wide open throttle, WOT, RPMs are 5,200 and your max RPMs for your motor are 5,600 then you have too agressive of a prop on the boat. You can drop 2" in pitch off the prop, a 24 pitch prop, and your WOT RPMs should go up to 5,600 giving you better performance. The prop will bite better because it is a lower pitch and will turn faster because the engine can run up to the specified max. Similarly you can drop from a 5 blade to a 3 blade prop and keep the pitch at 26 and your RPMs will go up to 5,600.

Now if your max RPMs are 5,200 and at WOT your motor is running 5,600 RPMs then you are under propped. You would need to increase your pitch from 26 to 28 pitch to bring your RPMs down to where they can safely run within the manufacturers specifications.

Now the general rule is adding extra blades, from a 3 to 4 blade prop, will slow down your speed due to the extra drag. That isn't necessarily true. When you are getting to that detail of props it all depends on the prop style, the pitch, the cupping, the prop venting, and who made the prop. Another factor is the prop slipping in the water. On my boat I had a 3 blade aluminum 21 pitch prop, the RPMs were 100 under the max. I switched to a performace style 4 blade stainless steel that was 19 pitch. The extra blade and stainless were to counter the RMP increase from dropping 2" in pitch. The 4 blade stainless prop ended up having better bite, got me on plane faster, and it ran about 4 MPH faster!

To get the max out of your motor it will require a lot of trial an error. There are prop calculators out there that take your current specs and speed and figure out how much prop slip you have, other calculators help you figure out who props should work. The results you should get on paper vs your actual results are 2 different things.

I have a ton of information on this. If you have questions just ask.

[CTFSHWHISKER]

talk to a reputable dealer who has set these boats up and they should eliminate a lot of trial and error,you are heavy with less than max hp if you have a 19 foot ranger. a trophy with the pvs vent system works great on rangers and you will probably get good holeshot and top
speed around 54-56 depending on what you haul start at 23 pitch.

[yogio]

I have a 18 foot nitro with a 3 blade, I think 23 degree lazer prop, and only a 115 merc... and I can do 53 mph...You should be able to get 60+ mph out of yours if I can get that out of my clunker.

[mattplapp]

For most F/S that size with a 150 you should be in the low 50's. Some of the 60's you saw on this board were from f/s's with more of a Bass Boat Hull than your boat. The ranger and Triton are on more of a Deep V or Multi-Species Hull than most boat companies which gives you better performance at low speeds (15-25) for skiing, but also gives you speed in the 50's.

Matt