Good WOT RPM?

scoutabout

Lieutenant Commander
Joined
Oct 14, 2006
Messages
1,568
This past weekend at the lake I trimmed the Scout and its 90 Yamaha 4-stoke out to a max GPS-confirmed speed of 65.4 km/h (40.3 mph) with the motor turning at 5700 rpm. The painted steel prop has "19 K" stamped on it which is the pitch I assume, although I've never seen a letter designation on a prop before.

Can anyone tell me if these are the rpm numbers I want or am I over-revving? The engine is certainly screaming at those revs but there is no indication of a redline anywhere that I can see on Yamaha's digital tach.
 
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