normal cruise spd under power (15HP)

[1-Tntimbo]

No water skiing here (LOL)!

I am looking at a 2000 model nicely equipped X with 15HP, 4-stroke. I originally thought I might want a 50-60 HP, but I am not a go-fast guy on the water. I once owned a 29 Topaz Sport-fisher with twin chevy's that would fly. I paid for that at the pump.

I can see a bigger motor would be of value evading a storm or at the end of the day, but really think the smaller engine would meet my needs 90% of the time.

Curious about fuel burn and cruising speed w/15HP, ballast on board and without ballast.

90% of my use will be lakes and intercostal.
T

[iredrider1177]

I originally had a 9.9 merc on mine. I could do about 7mph. Ballast in 3/4 throttle. Higher wind and current caused me a few issues in tight areas. Fuel consumption almost un noticeable. But so is my 60 at low rpms.

[Tomfoolery]

I can't give you any fuel burn rate info on that type of engine, but since you won't be exceeding theoretical hull speed, and shouldn't be trying anyway, you should get very good mileage. 10 hp is plenty for that boat in normal conditions, even with some wind, and the extra 5 hp may prove to be useful at less than hull speeds when punching through waves. Since the boat is so light, even with ballast in, you'll probably find it 'stalls' when it hits a wave, which is where the higher thrust of a bigger OB can be very useful. Just imagine yourself walking against big waves at the beach - while you have a terminal speed in still water, you can't go as fast when you keep getting knocked back by waves. Kinda like towing another boat or dragging a drogue, where getting to hull speed isn't possible, but you can actually use the extra thrust to fight through what's holding you back.

Some extra oomph for all those knock-backs can help, and you can run it at a reasonably slow speed for normal motoring and get good mileage. Running it hard will only use more gas and not get you there any faster, as 15 hp isn't enough (by a lot) to climb up onto the bow wave and plane.

[ronacarme]

We bought our 2000X new with a 9.9 Evinrude 4 stroke long shaft and re-engined, after OMC went bust and its nearby dealers disappeared, with a 9.9 Honda 4 stroke extra long shaft (which keeps the prop well under water and pushing in Lake Michigan waves experienced so far...say up to 5-6 feet) .
Both engines are hi torque models wih low pitch props (7"??? and 6.5", respectively) and accelerate the boat positively in forward and reverse with ballast and gear and 4 adults aboard.
WOT with these engines gave about 7.4 and 7.2 mph, respectively (flat water, low wind), about theoretical displacement hull speed for a 23 foot waterline. Removing ballast and gear and excess people would not raise max mph noticeably with a 10-15 hp motor.
I would guess our average motor cuising speed is about 5 mph, with a little motorsailing at lowered throttle settings. Our seasonal average mpg numbers for the Honda in the 2007 - 2011 seasons were 12.5,14.5, 15, 13.2 and 13.4 , respectively..
We find that motoring into 3-4 foot Lake Michigan waves at more than 5 mph, even bearing off at 30 to 40 degrees, results in pounding and a lot of spray and a rough ride.
We bought the X for interior livability and under 3500# trailerability, not for planing powerboat speeds, and have been happy with it.
Ron

[bartmac]

We have a 26X with a Suzuki 15Hp four stroke c/w high thrust prop......and get about 10-11km/hour on our GPS with ballast in...Revs about 1/3 but don't get any more speed revving harder...fuel consumption is very low...under 2 litres/hour

[dlandersson]

I have a 97 Mac 26X with 50HP Merc, and I almost never go faster than 6 knots - and that's in and out of the marina.

I don't even think about going out if the waves are much above 2-3 feet.

WOT with these engines gave about 7.4 and 7.2 mph, respectively (flat water, low wind), about theoretical displacement hull speed for a 23 foot waterline. Removing ballast and gear and excess people would not raise max mph noticeably with a 10-15 hp motor.
I would guess our average motor cuising speed is about 5 mph, with a little motorsailing at lowered throttle settings. Our seasonal average mpg numbers for the Honda in the 2007 - 2011 seasons were 12.5,14.5, 15, 13.2 and 13.4 , respectively..
We find that motoring into 3-4 foot Lake Michigan waves at more than 5 mph, even bearing off at 30 to 40 degrees, results in pounding and a lot of spray and a rough ride.
We bought the X for interior livability and under 3500# trailerability, not for planing powerboat speeds, and have been happy with it.
Ron

[Catigale]

Great thread on one of my favourite combinations...

Note small outboards double the rule of 1 gallon per hour per 10 HP rated.

[bartmac]

Note small outboards double the rule of 1 gallon per hour per 10 HP rated

Would that be at normal RPM ???? ie 3/4-full....because that's not our experience with a 15hp Suzuki at 1/3 rpm (guesstimating RPM...definitely less than 1/2)...also finding running probably even slower to reduce noise