RPM @ Ttop Speed Question PLEASE!

[Speedboat]

Just measured and adjusted Prop To Pad from 4 1/4" reset to 3" PTP. Boat a 2000 18'Stratos with a 2013Mercury Pro XS 175 hp. The Prop I'm running is a 3 blade Tempest 23P. This prop was worked but don't know what was done to it before I got it. Able to lake test tomorrow due to lousy weather. My question is what would be safe rpm's at WOT ? If any info available Please if anyone would give me I sure would appreciate.

[jimsch]

I would say no higher than 5500 rpm for a 2000 motor, see link below.

https://www.rubexprops.com/boat-prop.../?make=Mercury

[Speedboat]

Thanks jimsch for the help and the information. I noticed that i posted the motor as a 2000 but it was a replacement motor and was a 2013 Mercury. I went to the referenced address That is kind of what I was going to follow. Before all these adjustments i was only getting around 65 mph whenever I went WOT, which isn't all the time. Last time I went to lake i tried WOT just to see what the boat would do and only got 50-55mph therefore I checked PTP to find it was 4.25" So made adjustments to what appears to be 3" PTP. Hope to go out tomorrow to Mayo Res. near Roxboro and hopefully performance will be good. Thanks again jimsch.

[1BADAIR]

Small adjustments can go a long way. 1/4” can do wonders. 1.25 might be a bit much

[jimsch]

Dan, you can try it where you set it but watch the water pressure. 3" is where I'm running my 2014 200 opti at.
TBH, I would try it at 3 1/2 to 3 1/4, as 1BADAIR stated, small adjustments can work well.

I'm running my 200 at 3", if I go to 2 3/4" I can pick up more speed but fight other issues. 3" is a no hands drive.
Anything less makes it very loose, I like easy.

[sabreski]

I have an 08 175proxs. RPM for that engine is 5,750-6,000. The tempest likes to run high, but the engine does not have low water pick ups & you will run out of PSI. A Fury 3 blade should be better as it likes to run deeper-perfect an engine without low water inlets. a 2000 era merc 175 efi has no limiter-wish I had one.

[Speedboat]

Thanks Folks. Cold as it is forecasted believe I'm going to a nearby lake to make the change of the prop to pad from the 3" to where is best at 3.25" first thing then do the lake test. I was going to make a lake test as it is now, at 3" PTP, but think it might be best to drop the motor a bit to make the PTP 3.25" then lake test. All was good with this rig several weeks ago, run close to 60mph @ just under 6000rpm with around 12psi water pressure. I hit something a week ago I believe knocked the PTP out of wack, now working to reset the prop to pad to3.25" as it was. Just have to make the adjustments, lake test to see if I got the performance as it was or should be.

[bassdge]

Hitting something changes everything. If you hit something you likely bent the prop , loosened the prop hub, or bent the skeg. It is doubtful that an impact moved the motor down. Best to provide all information up front before someone can give you proper advice

[jimsch]

You might get the unit checked out, hitting something when running can cause many issues.
Bent Prop shaft, seals and vibrations can lead to much more if run.

[Speedboat]

I agree bassdge and jimsch hitting something with boat shouldn't affect the prop to pad setting. Right after I thought I may have struck something I ran to the ramp to load up and go have everything with the motor checked out. While on the way to the ramp I didn't feel any vibration or abnormalities in motor operation. Once in the parking lot of the marina I visually checked the prop to be OK. I pulled the prop to see no problem. Only thing I found was a stopped-up pitot tube hole to the speedometer (that has been disconnected for some time). I had the prop shaft and seals check where all checked OK. It was when having lower unit and prop checked that the prop to pad setting was called to my attention. The prop to pad I check but it was a few years ago. Now, I had noticed before the floater issue I felt the top speeds of my Stratos wasn't the best it could be. That's where I am now. Now to be safe I'm having everything checked again.

[wareagle24]

Thanks Folks. Cold as it is forecasted believe I'm going to a nearby lake to make the change of the prop to pad from the 3" to where is best at 3.25" first thing then do the lake test. I was going to make a lake test as it is now, at 3" PTP, but think it might be best to drop the motor a bit to make the PTP 3.25" then lake test. All was good with this rig several weeks ago, run close to 60mph @ just under 6000rpm with around 12psi water pressure. I hit something a week ago I believe knocked the PTP out of wack, now working to reset the prop to pad to3.25" as it was. Just have to make the adjustments, lake test to see if I got the performance as it was or should be.

I saw where you posted this in another forum. Since you were only running 5-10 mph and the stick was smaller than a baseball bat, there's no way that it knocked anything out of whack.

[Speedboat]

I saw where you posted this in another forum. Since you were only running 5-10 mph and the stick was smaller than a baseball bat, there's no way that it knocked anything out of whack.

As I also Thought also. It was just after I felt I struck something whatever i noticed my top-in wasn't what it had been. I checked my records and the last time i checked the PTP on the motor and boat was a few years ago. That said i went to jordan this morning and did just that, checked the PTP and as stated it was at 3". I made the correction and reset it to 3 1/4". Afterward I made a run in the fairly strong winds and decent choppy water of Jordan @ near 60mph , 50167 rpm, and between 12 - 14 PSI water pressure. That is much better than it was. Anyway I checked the prop to Pad and today I spent the time and made a detail check and corrected and set the PTP to 3 1/4" Thank the Good Lord that is all done no!