What Prop?

[jorgeinmiami]

I have a 3 blade SS prop that the Po gave me with the engine (also 2 other aluminum props) On the SS one it has the following stamped on it

17-M and D094D

i imagine the 17 is a 17" pitch? but the rest is???

What would be the "best prop/size to run with
20MA with a 150 Black Max late 80's

[Blue197320]

try my 15x17 as a good start. ran good when i had a 150

[Blue_Heron]

I played with several props on my 20. On a Potter 20 with a 150 Merc, I would start with a Mirage 17p.
Dave

[jorgeinmiami]

Evan Thanks for the offer when I get ready to hit the water I'll call you maybe we can take both of them out just in case I need a tow...LOL

But anyways is there any way to figure out what size prop I do have?

Right now I have a lot on my plate with family members and their health issues so the boat is on the back burner

[McGillicuddy]

Jorge,
You prop appears to be an older Yamaha semi-cleaver probably 14" diameter by 17" pitch. Could also be an old Force prop. Unless you find an old prop catalog from the '80s it will be hard to determine exactly as most folks don't document the specifics of their prop. The prop will be a decent match for the MA w/150 Merc combo, but you can do better. It has stern lifting qualities and should turn close to your target 5800 rpms or so.

Probably get you 40 mph at top end +- 2mph. I think a PowerTech MQS3-16 pitch will be your best bet.

To measure diameter, place the prop on a work bench take a square to the edge of a blade and use a tape measure to measure the outer-most point of the blade to the center of the prop hole. That number x 2 is your diameter.

To confirm the pitch a prop shop can lay it on a semi-cleaver repair mold and give you that.

[Fr. Frank]

Originally Posted by McGillicuddy

Jorge,
You prop appears to be an older Yamaha semi-cleaver

That's exactly what it is, Jorge. The 17-M series props are the early Yamaha salt-water props, and provide as much stern lift at high RPMs as the Mercury Mirage. Their weakness is in a reduced rake progression on the outer 1/3 of the blade, which gives them great top-end performance, but weakening their mid-range performance. They run very well as a semi-surfacing prop for WOT/high-rpm performance, with slip ratios that can be down around 8%, but have higher 15%+ slip ratios at greater running depths, at mid-range RPMs.

[eggsuckindog]

Not sure what that design actually is, not much cup or blade area but cup could be added but prolly not worth it - I had a little tip ding, hub and brought to spec and it was 150 just as an FYI


I mentioned before the design of the Stilletto's are great for us, a 17" would be the proper size. Engine height based on my experience would be the cav plate 2 1/2" above the hull bottom. I get no cavatation there at all and just stellar trim responce, it holds the bow up and holds it down - whatever you want, I can't imagine anything else working better. The Mirage + was a big favorite on here for awhile, it is a similar design to the Stilletto but has more Dia @ 15" vs 14 1/4 - never found one to try so can't comment on them.
Bigger blade area probably would work well on a 23, not sure on a 20, although I found one at my marina used and after talking with the guys that had tried it they suggested I stick with mine - raised the motor a hole and it lit it up, so glad I kept mine.

My original prop was a rounded ear Merc, closest thing I could find was like a Vengence - it was horrible compared to this, even my inexperienced crew noticed in 10 min

I saw Stilletto's new on google search for 250 to 285 which I thought was pretty reasonable - I got mine used for 150 from a friend

[jorgeinmiami]

Took prop off in the back side it reas 13 1/4 x 17

So i guess this will be a spare or sell it as I have 2 aluminum props for spares

But for the moment it is what it is

So from what I see here the one I should look for should be a Stilletto 15 x 17 or a Mirage + in the same size???

But as the budget improves I can knock that off too.

Now the list is getting some what smaller but with bigger ticket items such as

Change lower unit seal and impeller
Prop
Leaning Post
T Top
Garmin 740s
And a lot of little things
Aluminum Trailer (next year)

I need that long lost relative from some small nation in Africa that I have never met to send me the $50 million he said he was sending me via Western Union quickly

[FishStretcher]

For what it is worth, my 20 MA came wth a Yamaha and a 13-1/4 x 17 M stainless prop on a 175 two stroke. So it might not be a bad place to start.

[bumpdraft]

[QUOTE=jorgeinmiami;203769]I have a 3 blade SS prop that the Po gave me with the engine (also 2 other aluminum props) On the SS one it has the following stamped on it

17-M and D094D

i imagine the 17 is a 17" pitch? but the rest is???

I have an older Yamaha Salt Water series prop marked 17-M and from the Yamaha website; for outboards from 150-300 hp.