We were out on the water today doing some testing. I had a fellow 26Xer on the boat and had him firewall the throttle and drive around. He really enjoyed the ride and said this is the way it should run. I agree.
Heads were turning when our sailboat was flying by.
Eric and I were stopped his 90Hp 26X by a power boater a couple of months back at Emerald Isle; the guy took some cell movies and said "I ain't never seen no sh*t like that before!"
just out of curiosity, what is your fuel burn rate at WOT?
I have had to quite literally "throttle back" on my consumption, because I don't have access to a refuelling station within 6 hours sail, and the local petrol (gas) stations in Hong Kong won't sell me more than 10 litres (2 gallons) at a time in a portable container (not even my pukka 25 litre Honda can).
As I get above about 4,000 rpm the rate at which I use fuel seems to rise exponentially - maybe 1/2 a gallon per hour at displacement speeds, a gallon at 10 knots, double that at 14 knots and, if I ever get to WOT in the 15 - 17 knot range*, then it's more like 3 1/2 or more an hour.
* As I have made clear on numerous occasions, I despise my Honda BF50 with a vengeance, and for numerous reasons. However, top-end, I am now coming to suspect that the WOT performance is not all that bad. I quite seriously have seen a repeatable 17 knots, ballast out, mast and sails on, boards up, bottom paint on, and even now with all my silly kit on board I can hit 16.5 knots at sea. I don't like to, as I still haven't figured out the refueling conundrum and consequently tend to potter about between sails, but I am coming to the opinion that although it's pants lower down in the rev range, the BF50 may confer some advantages as I open the throttle up. Incidentally, my throttle is increasingly becoming an "all or nothing" affair, and will often "stick" in full-open mode. Is this a lube problem, or more likely an adjustment issue at the motor end?
If you're getting 17 knots out of your BF50, you're getting everything I've seen out of my ETEC-60 with the boat completely empty excepting 600 lbs. of humans. Certain that you're looking at knots and not MPH? It's hard to believe a 50 is actually hitting 17 knots.
My fuel consumption rate at WOT is 3GPH as indicated by the fuel flow sensor on my engine. Keep in mind that with an outboard motor, doubling the speed uses 8X the fuel, so yes, the rise is in fact exponential. It sounds like your speed/fuel consumption is almost exactly the same as mine. Given that we have no silly fueling restrictions, I have about a 200nm range with 24 gallons on board at 5 knots. Since we bought the boat six months ago, I've used about four gallons total as we generally sail and the admiral and mates don't like speed boating.
GPS SOG in Dubai in 2009/10 was a repeatable 17 knots in both directions - ballast out, mast and boom and sails on, moderate kit, two bodies on board, bottom paint. http://www.macgregorsailors.com/forum/v ... 09#p176503
That has dropped this year to 16.1kts repeatable, though the sea conditions in HK are slightly less favourable and I am carrying slightly more kit.
To be honest, it's fairly academic, as I don't blat around that fast - especially not with my local refueling problem - and I still despise the BF50 because it lacks punch lower down the rev range and can only spin a narrow prop with a relatively coarse pitch, rather than a nice big fat one with a large blade area for punching through crud at "real world" speeds
Engine performance can vary from area to area, due to differences in fuel quality, also. My marina has non ethanol premium fuel and there has been a 500 RPM increase with it in my Suzuki DF50, compared to the 10% ethanol fuel from the gas station. No other changes in weight, or weather
Cat,
Last year coming back out of the Rideau we had to get a couple of gallons topped up in order to make the last lock. What the little dock attendant didn't mention was that they were empty and waiting for the truck to arrive. Regardless, she tried for a few more bucks (a big powerboat had drained them just before me - I met him later and he told me he only managed half of what he needed.) and delivered me two bucks worth, mostly water and gunk. The top up we got some miles later probably saved our bacon.
Had I realized what had happened then and there - I would not have been polite!
Hamin' X wrote:Engine performance can vary from area to area, due to differences in fuel quality, also. My marina has non ethanol premium fuel and there has been a 500 RPM increase with it in my Suzuki DF50, compared to the 10% ethanol fuel from the gas station. No other changes in weight, or weather
~Rich
Yeah, I'm guessing there's not a lot of ethanol in Dubai gas.
