CD25, Honda 150 performance chart

[Minnow]

CD25 Honda BF150 Performance Chart
I had received several requests for this info, so I thought I would post it here.
Conditions on the Delaware river this morning; 70 degrees, no wind, flat surface, slack low tide, 2 people, 1 very large dog, half tank water, half tank fuel. Medium load of gear. Tabs fully retracted. Solas 14 X 19 SS 3 blade prop. Speed from GPS, fuel flow from Honda digital gauge. Range based on 90% of 107 gal tank.

RPM MPH GPH MPG Range
660(idle) 3.5 <.5 --- ---
1000 4.7 .6 7.8 751
1500 6.4 1.0 6.4 616
2000 7.9 1.4 5.6 539
2500 9.4 2.2 4.3 414
3000 12.0 3.4 3.5 337
3500 14.7 4.6 3.2 308
4000 18.0 6.1 2.9 284
4500 25.0 7.5 3.3 318
5000 29.0 10.1 2.9 279
5500 32.5 13.4 2.4 231
5520(WOT) 35.5 14.0 2.5 241

In conclusion, this motor / boat combination is all sweet spot, running happily at any speed in flat conditions. Running in one to two foot slop, the boat was happiest with the tabs partly down and speeds below 25 mph. The transition from displacement to plane is very subtle, happening around 11 mph.
P.S. A big thumbs up on the Wallas. Running last week starting out with frost on the docks, and a pot of coffee brewing by the time I made it to the main channel, I thought that life just doesn’t get much better than this!
PPS. I had a feeling the chart formatting wasn't going to work. Maybe the head nerd could fix it for me?

[stevej]

Thanks for posting the info Minnow.

Been toying with idea of repowering with one of the 150hp 4-strokes so it's nice to see some real results. Mileage numbers are about what I expected but little surprised by the top end speed.

My 115hp 2-stroke gives a flat 2.2 to 2.5 mpg and tops out at 28 mph
From a mileage perspective looks like 20 to 30 percent increase at cruise speed.

Tough to justify from a fuel cost savings perspective but there are several other benefits such as the increase in range, the ability to add a third battery (no oil injection tank) the environment factor......

Wish they were a little less proud of the new additions last price check on the Yamaha was something like 12 grand with base instrument package so may run the 115 a couple more years.

Anyway thanks again for the numbers

stevej

[Les Lampman]

Hi Minnow,

Wow, it's great to hear you're out on the water!

IMHO, you're swinging about 2" too much pitch on that prop. The 150 really ought to be able to reach the high 5's (I'd go for 5800-6000 at your current weight) and when you load the boat you'll appreciate the extra mid-range punch when climbing the backside of a wave, etc. And the slighly slower water speed at idle rpm won't hurt either.

It's a rare Honda that can swing a 19" pitch prop. Has to be a high power-to-weight ratio setup; which we ain't!