posted 05-05-2002 09:54 PM ET (US)
Well - finally got a good day on the river. Put 63.0 miles on the new motor today. Here are a few numbers. Water was smooth but swift - boat drifted downstream at 3.6 mph with the motor off Probably not an extremely accurate measurement of current given wind and drag but close.Boat planes completely at 20.5 mph. I then back off to 17.5 mph without slipping off plane.
Traveling downstream with the current I noted the following speed vs. rpm's. All speed measurements GPS averaged over several minutes. Prop is 21" pitch merc black max.
Load Myself and dog - 300lbs. (he's a big dog) 24 gallons fuel @ start of trip.
21.5mph @ 2,950rpm
24.0mph @ 3,200rpm
26.0mph @ 3,400rpm
28.0mph @ 3,600rpm
30.5mph @ 3,800rpm
35.5mph @ 4,250rpm
38.0mph @ 5,000rpm
42.2mph @ 5,250rpm - WOT any more trim broke prop lose.
Traveling upstream the maximum speed I could get was 36.7 @5000 rpm which was completely trimmed out.
Fuel usage (based on float guage)
When I turned for the final run back to the dock guage showed 3/4 tank. When I arrived, 29.6 miles later guage showed 1/4 tank so I used approximately 6 gallons which = 4.93 mpg. Given the inherent inacuracies of float guages I would not hesitate to shave this down to 4.0mpg - good enough for me.
I tried my best to hold a speed of 22 (3200 rpm) the entire trip back but did open it up for a mile or two of this distance and came off plane twice while negotiating my way around a couple of barges.
Heading to Raleigh for a few days so I'll be out of pocket starting tomorrow. If I don't respond to replies - I'm not being rude.
See ya,
Ll.