Another Marina mistake - pitch for feathering 3 blade prop

[Chris Martinson]

While I normally do most work myself - I had my marina replace my cutlass bearing.  Unfortunately - they botched it relating to my prop.  The "mechanic" who took it off didn't mark or notice the pitch of the blades - he claimed he was familiar when I asked him...apparently not.  When I went out this weekend for the first time - no power.

I have no info from the previous owner -no manual or original settings - it is a PYI max  3 blade feathering prop.  The year of my boat is 1989 with an M25XP and the Hurth transmission - I believe 2:1- does anyone know what the pitch should be so I can start the long and contentious process with the marina about getting it right.  I suspect they won't be too keen on hauling every week to get it right....I've only heard horror stories about the length of time to get it set right.Also - any ideas on how to be sure it is set correctly?  I will contact PYI on Monday and see if they can help....any assistance will be greatly appreciated....thank you.

Chris Martinson
Hull #945

[Mike Vaccaro]

Chris,

18 degrees should be a good start.  "E" on the x-axis and "H" on the y-axis (right hand rotation) according to the installation manual on the PYI website.  This will correspond to 9.2", which is close to the stock, three-blade fixed pitch.  The next max prop setting is 20 degrees, which would correspond to "K" x and "E" y.  This is 10.3" and bog the engine down a bit, but should be fine (quite a few folks have re-pitched there fixed wheels to 10").

Here's the link to the instructions:  http://www.pyiinc.com/index.php?section=max-prop&action=three-blade-classic-installation&sn=3

Best of luck,

Mike

[Ron Hill]

Chris : If Mike's calculations are correct, then you could go with either setting. 
I recommend that the pitch of the fixed "Sailor" 3 bladed prop be 10.5 inches. 
I have mine (3 bladed fixed) pitched at 11 inches with a M25XP.  Your choice. 

[Craig Illman]

Ron - I saw this old thread while researching "cutlass". I have a 15x10.5 on my '91 M25XP-A, I was thinking I was over-pitched because I max out at about 2600 RPM, but I don't observe any smoke. Now, I'm thinking maybe I need to have the injector pump rebuilt like you had done. My question is, with your 15x11, what is your boat speed at 1000 RPM and 2100 RPM? I do about 3.5 & 6.2kts.

Craig

[Tom Soko]

Craig,
Is it possible that your tach is out of calibration?  I think I would check that before I went thru the trouble of any rebuilds.

[Craig Illman]

Tom - I think the tach is pretty close, it'll run up to 3200 in neutral. I should ask to borrow the optical tach from Mr Senator. I'm proably going to do a compression test this weekend to see where things stand and decide if things warrant addressing this winter or the next.

thanks for the feedback.

Craig

[Ron Hill]

Craig : I do about 6.5kt at cruise rpm (2400) with a clean bottom.  I have a mechanical tack that's good so I've given you the actual RPM - NOT tack instrument readings. 
When I rebuilt my injector pump the problem was that the engine had NO power (torque) under power.  It had the 3200 RPM, but I couldn't get above 1600 (actual) rpm in gear!!   
So check your out that way.