You want to book mark this page:
http://www.yanmarmarine.com/products/pd ... chData.pdf
That is the tech data for your JH/4JH4 HTE 110 hp diesel. This gives max rated hp at 3200 RPM. The max torque is at 2000 RPM. Some say you don't want to run a diesel at more than 85% of max RPM--or 2700 to 2800 RPM. Some say max RPM minus 200 RPM. At 2800, according to the spec sheet, you are burning 4 gallons an hour, and will be close to 70 hp prop output. At 3000 RPM you are developing 90 hp prop output and burning just under 5 gallons an hour.
In Oct I did some runs on a light C Ranger 25 with the 125 hp engine:
Note speed in statuate miles per hour vs nautical miles an hour.
Idle (650 RPM) 3.1 Miles an hour 2.7 knots
1000 RPM 4 Miles an hour 3.5 knots
1600 RPM 6.5 Miles an hour 5.7 knots
2000 RPM 7.5 Miles an hour 6.5 knots
2500 RPM 8.8 Miles an hour 7.7 knots
3000 RPM 11.2 Miles an hour 9.7 knots
3200 RPM 13.2 Miles an hour 11.4 knots
3400 RPM 14.5 Miles an hour 12.6 knots
3600 RPM 16 miles an hour 13.9 knots
3800 RPM 17.5 Miles an hour 15.2 knots
The spec curves on the two engines are significantly different--but the 125 hp engine developes 70 hp at about 3000 RPM.
I would expect slightly less speed with the 110 hp engine--but I personally would consder it an 8 to 10 knot boat for practical purposes.
I am sure that owners of the 110 hp engine will jump in with their experiences once the boat is loaded for cruising.