Back from Florida with new motor,
Over the Thanksgiving Holidays a few folks helped themselves to my 2005 Yamaha 300hpdi outboard. Since I bought the boat in Pensacola when I lived there, I took it back over Christmas to be re-powered by Steve Johnson. Owner of the late North West Florida Marine. My power of choice was a 2010 Suzuki df250. I had Steve break it in before I got there so I could just run it like mad when I showed up the first week in May, and thats just what I did for 7 days straight. Here are the real life numbers and comparisons between a 2005 Yamaha 300hpdi 2 stroke and a 2010 Suzuki df250 4 stroke. The boat,and load are the same. 2005 Blazer Bay 2420, 6 inch Bob's jack plate, trim tabs, trolling motor, 4 optima batteries, 2 guys, some gear, and 40 gallons of fuel.
~Yamaha with 14-1/4 diameter x 23 inch prop, mounted on the third whole down. Boat would jump on plane with little bow rise and in a few boat lengths. Cruise was 35 mph @ 3500 rpm getting around 3.7 miles per gallon. High cruise was 40 mph @ 4000 rpm getting 3.15 miles per gallon. Top end was 60 mph @ 5350 rpm getting 2.4 miles per gallon. The power came on in the top end and burned alot of oil.
Suzuki with 16 inch diameter x 24.5 inch prop, mounted as low as it will go. The low end and mid range power on this motor is incredible, much stronger than my Yamaha up to about 5000 rpm's, then kind of levels off. Boat jumps on plane with very little bow rise, and in about half the time. Cruise was 32 mph @ 3000 rpm's and getting 5.8 miles to the gallon. High cruise was 43 mph @ 4000 rpm's getting 4.6 miles per gallon. Top end was 56 mph @ 6000 rpm's getting 3.8 miles per gallon.
These numbers are from Yamalink fuel management gauges and Suzuki's fuel management gauges, speeds were off of my Lowrance 520c gps. The Suzuki required more jack plate adjustments to get the best top end, while my Yamaha just trimmed out and flew. Very happy with the Suzuki, and it's not burning any oil.