Engine mount height

Roy,
It will be interesting to see what WOT and higher speeds are. That engine should be close to 6,000 RPM at WOT, and I would think that a light boat should be in the high 20's at sea level at WOT.
 
thataway":ocgo8bzm said:
Roy,
It will be interesting to see what WOT and higher speeds are. That engine should be close to 6,000 RPM at WOT, and I would think that a light boat should be in the high 20's at sea level at WOT.
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Just as a data point, the manual for my 2002 F80 calls for a "full throttle operating range of "5,000-6,000" rpm. I don't know if other motors (or a 1999 F80) are the same though.

If I remember correctly, I got around 5,600 and 28 (not as sure of my memory on speed; might have been a touch higher) at WOT with a relatively light boat (two people, full water tank, heavyish kicker, and not much else aboard). That said, I've since fit a new (different) prop (and a Permatrim), and I'll customarily not have such a light boat (just a few new variables!), so I'll have to re-test once I get back in the water.

Sunbeam
 
Yesterday I posted: After yesterdays sea trail: at 3600 rpm, a speed increase of about 0.7 mph (13.4 mph, up from 12.7 mph) with engine raised 2". This is with bow riding noticeably lower with PermaTrim/engine trimmed to almost max down. I actually lost 1-3mph by trimming engine up, which raised the bow. Top of PermaTrim now rides just 1-2" below water surface at this speed.

I don't know why I ststed "MPH' when I have both GPS's set for nautical speed. Thus my 13.4 was actually nautical x1.15= 15.4mph. That sounds a little better. Next time out I plan to run and record speed at each 500rpm increase at best speed trim.
 
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