Does this look like a slipping prop?

archcycle

Chief Petty Officer
Joined
Sep 21, 2009
Messages
647
1990 140hp johnson / 16' cape horn deep v

Do these pics look like this prop is slipping? The pictures are of a loaner from a local shop after running it saturday and sunday. My current prop is 15x17 and in rough water or when heavily loaded I'm maxing out at 5k but with a light load in flat water it planes out to 5500+. Shop guy loaned me this 15x15 (shop tuned measurements) to try out. The boat really seemed to like it at the lower RPMs but I got some really diminishing returns as it went up.

Running 4000rpm under a heavy load in ok water it went a steady 26mph, and turning 5600 WOT it bumped up to a max speed of 31mph. 40% increase in engine rpm only resulted in a 19% increase in speed.. something seems wrong there.

The balled up stuff on the forward side of the prop seems to be rubber from the hub.

prop1.jpgprop2.jpg
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: Does this look like a slipping prop?

Moving to the Prop section. Good luck!!
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,510
Re: Does this look like a slipping prop?

Ayuh,... There's no way to tell by lookin' at yer pictures,...

Scribe, or paint a line across it, 'n run it, then look at the line to see if it moved...
 
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