Originally Posted by Burdick
Wish I could get over 40 knots out of my DF140. 35/36 knots is all I can acheive with 21" ali prop at 5300 revs on a very good day. I accept my boat is bigger and heavier but a chum of mine has an identical boat and set up and he will get over 40 knots out of his. Engine in for a 190 hr service today so will see if that helps.
one thing might be to look at is the travel on the throttle and make sure it is opening the throttle fully on your boat, poorly set up controls can cause all sorts of issues