Stainless Prop Question

CAVU

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This weekend I finally swapped out my aluminum prop for a new stainless Reliance 17P. I have the Yamaha F200 HP 4 STROKE 2.8L 4 Cylinder 25 IN. We have a 22ft SSRFBXP with the SPS hull. At speed the the engine runs smooth as silk and I seem to really be getting a sense of a lot more torque.
There seems to be a new shimmy or vibration when at idle in gear both forward and reverse not evident with the aluminum prop. The top speed seems to have also diminished with the stainless propeller. Unfortunately, I do not recall my RPM's and I wish I would have done a better job of before and after data. From what I recall, I was hitting on GPS around 37.5MPH with 4 people and half fuel with trim adjusted. With similar fuel and passengers the stainless lost about 2MPH. Engine is mounted in the top hole. Any feedback appreciated.
 
Prop Thoughts:
We have a 16p Enertia on our 200 Merc. Verado Pro. My guess is your pitch is a little too much...drop it down 1 or 2. With rpm data you should be able to estimate fairly well how much to drop down (gain approx. 200 rpm per drop in pitch). Since the prop change lost you speed, something is certainly off here

Engine Mount Thoughts:
Where is your cavitation plate when on plane? Curious if your engine mount is a little off. All of that said, I’d expect you to pull down 40 mph (or slightly more) for sure with a SS, so something is off between diameter/pitch and hole mount. If sitting too low in the water, that certainly would create a bit of drag, but assuming its where it was at before, this obviously is not the main issue (if its an issue at all)

Proper Chatter Thoughts:
Never had any prop chatter before, so cannot speak to that.
 
A 15 pitch reliance on this motor is perfect.
 
Yep. Prop rattle. Or chatter. My 115 did it with a stainless prop, but not with an aluminum (softer). You can buy a flexible hub that will absorb the chatter. What's happening is each time a piston fires, since there's no transmission like a car to dampen each explosion, the prop feels the brunt force of every piston explosion since the gears are essentially a direct connection between the pistons and the prop. A hard stainless prop will rattle because there's always a little slop in the gears and hub. Each "tick" of the rattle/chatter is a piston exploding into it's power stroke, and so the prop "rattles" at low RPMs. It goes away at higher RPMs because the greater friction of the water at higher RPMs keeps the gears tight, and the rattling stops. An aluminum prop flexes and absorbs the impacts so it doesn't make as much noise, or none in my case. My 150 was the same way. Stainless chattered. Aluminum was quiet. But the aluminum prop performed MUCH worse than my Enertia (Thanks Todd!) so I bought a flo-torq 4 hub ($100) and the noise stopped.
 
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Need to know what your WOT rpms are with the reliance. Does this Reliance have the SDS shift damping hub? If not that is why you are getting chatter.
 
Depending on where you bought it, you may be able to exchange it, (if undamaged) for a 16 or 15 pitch.

The lessons here for anyone reading this are:

- always log your data... gps-verified speed, rpms @ WOT, number of passengers and weather & water conditions

- try to buy from a seller that lets you demo a prop prior to purchase

- try to buy from a seller who will let you exchange an undamaged prop for another, should the need arise.
 
Hmmm. When I put my Reliance 14.5 x 15 on my Yamaha F150 last year the smoothness was very noticeable with the complete absence of chatter. I put on the very latest version of the SDS prop which didn't require any special or extra parts. Just pull off the aluminum prop and put on the Reliance using the existing nut and thrust washer.

Earlier versions of the Reliance prop with SDS required a special plate or washer and even earlier versions had no SDS at all.

My RPM's at WOT didn't change significantly between the two props but there were many differences in overall performance.

As Randy said, speed, RPM and even an idea of trim at WOT are great indicators and comparators when diagnosing performance issues. Also, how high the motor is hung vertically on the transom is important. With yours and my Yamaha we have a 4 hole adjustment range to set the height of the prop and anti-cavitation plate with respect the flow of water under the boat at planing speeds. The lowest setting would be hole #1 and as the motor is raised, holes #2 through #4 respectively. I am currently using hole #2 (where the dealer hung the motor originally) and that has been satisfactory for me so far.

I know, clear as mud. My first and biggest question for you because you appear to still have chatter is where did this prop come from?
 
I'd also like to add for those following this thread that propping a boat correctly is an art... NOT a science. Yes, there are some quantitive rules to follow, but ultimately, trial and error will get an owner the best prop.

My dealer swore his guys take 3 props on every boat water test and select the "best" one. I called BS. There is no way any dealer is going to spend that kind of time.

I upped from a 13 pitch to a 15 pitch and dropped RPMs and gained 5 MPH (to 43). So, don't believe everything a dealer tells you.
 
I’m on prop #7 since I bought the boat 3 years ago. Lots of experimentation.....Reliance 14.5 x 14 (finally the right one).
 
My Yamaha F150 came wither the Ripeliance 14.5” 15P. I did lift the motor up one hole to gain a very little speed. No chatter with mine at idle F or R. RPM is 5900 - 6000 at WOT. Satisfied.
 
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My Yamaha F150 came wither the Ripeliance 14.5 15. I did move the motor up one hole to gain a very little speed. No chatter with mine at idle F or R. RPM is 5900 - 6000 at WOT. Satisfied.

Randy, if I read this correctly you went from hole #2 to hole #1? I only ask because I'm considering this change due to the popularity of the front of the boat (seems that no one wants to sit in the lounges when we're running). With the weight biased forward I have more tendency to "blow out" a bit when accelerating.
 
Chris, I moved the motor upward one hole, if that clarifies. The motor now sits .5” higher in the water. There’s not quite as much motor in the water after my adjustment.
 
Randy, the holes are number top to bottom as #1 to #4. If I understand you correctly you went from hole #1 to #2 taking the motor from its lowest position up .5". And in doing so you noticed no appreciable differences in performance?
 
Your set up should be pretty close Lakeliving’s boat. I thank Andy and the F200 and you 22’ g series should be the same length as his 24’ S. I think he’s at 44.
 
This is my first outboard, I have the Yamaha F200 I4 as well...What is the benefit from changing out the aluminum that came with it to the SS prop? Just curious. All my old boats were cruisers with BIII on them so SS props were the norm, and never had to look into changing them, so I admit I dont have a lot of knowledge with different props and what the accomplish. I saw 1 post that said the 15P reliance is a good prop...what is tht Thanks
 
This is my first outboard, I have the Yamaha F200 I4 as well...What is the benefit from changing out the aluminum that came with it to the SS prop? Just curious. All my old boats were cruisers with BIII on them so SS props were the norm, and never had to look into changing them, so I admit I dont have a lot of knowledge with different props and what the accomplish. I saw 1 post that said the 15P reliance is a good prop...what is tht Thanks

It actually surprises me that a F200 would even come with an aluminum prop. In my mind that is a cheap move by the dealer. I’d be very frustrated with my dealer if they did that to me with that motor.

With a 150HP and up you should typically have a SS. Aluminum is going to flex and lose performance, and the SS wont and maximize performance, with a 150HP and up motor. IF someone is shelling out big $$$ for the high HP motor, then I’d think the idea of trading some of it away needlessly with an aluminum prop is counter productive.

As for the best prop for your F200 I4, there are a number of people on this forum with that motor. I have a 200 Mercury Verado Pro supercharged I6. For me, a 16p Enertia is proving really good, and I could prop tweak it to a 17p Enertia.

Lakeliving in these forums has the F200 I4. I am pretty certain he is running a 15p Reliance with great results. Maybe check with him, or use the search function in the upper right hand corner of these forums to explore threads on propping and performance. Lots of information in a multitude of posts over the years. They really helped me out a ton when we got our boat in 2017.

Good luck!
 
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