Odd ball Props

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fryedaze

Guru
Joined
Sep 4, 2011
Messages
1,722
Location
USA
Vessel Name
Fryedaze
Vessel Make
MC 42 (Overseas Co) Monk 42
I recently had my props reconditioned. I had spares to install that were new and were 25 X 27. I assumed the props that were taken off were the same. When they came back from the prop shop one was 24.75 X 27 and the other was 26 X 26. You could see on the 24.75 prop that is was originally 26X26 but the numbers were xed out and replace with the 24.75 X 27. My guess is the PO damaged them and had to have them altered. Are those diameters and pitches equivilent? BTW the 25X27 that I installed performs much better. Idle speed was 3.8kts and is now 4.2kts. My cruise speed at 1500 rpm is up by .5kts. I still get a WOT that is almost the same at around 2600 rpm.
 
You'll get many opinions but my 2 cents worth would be to get new/s/hand/recon spare props at 25x27. Such an imbalance as the 'old' props will cause different engine loads, skewed performance etc.
Do it once, do it right, it might put a dent on your Visa card but the peace of mind is priceless.
 
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