We have the twin Lehman 135's in our 42' CHB Present Sundeck - semi-displacement. At 1800 rpm we cruise at 8.7-9.0 mph and burn about 3.5-4 gal per hour. Love those engines - as has been stated they are very easy to work on and they run fairly cool at 175 degrees consistently (especially after I installed two new water pumps
). But I did pull a bone-head issue a few weeks ago on the TN River - checked the strainer on the starboard engine, and then promptly forgot to re-open the sea-cock - burned up a brand new impeller
But again, pretty easy to repair.