40hp vs. 50hp engines with the same engine block (suzuki df40/df50)

[Rancherlee]

I'm looking to repower my pontoon and was looking to purchase a DF50 for it (its rated for a 60hp max). The difference in price is 800$ between the 2 and its only 300$ more to get the DF60 over the DF50 but its too tall to fully tilt up and I feel the 360# is just too much weight for this old pontoon and I already set the DF70, Johnson 70 4 stroke, on the back off my fishing boat. I put it in the water to see how it fit, sat, and run which was 26mph gps hitting the rev limiter with a 13 pitch aluminum prop and 3 people on board. Am I right in thinking that below 5000rpm both the DF40 and DF50 should perform the same since the 40 peaks at 5500 and the 50 at 6200rpm? I'm thinking the extra cost isn't worth it since it will spend 90% of its time well below 5000rpm. Also as another twist the dealer has a few used 1999 DF40's that he will sell for 2900$ out the door with controls, prop, and 30 day warrenty so I may go the used route.

 

[JB]

Re: 40hp vs. 50hp engines with the same engine block (suzuki df40/df50)

I agree that the DF40 will probably perform as well at low and medium rpm as the DF50.

The differences mostly move the torque curve and peak to higher rpm in the DF50 to make the added 10HP.

Think of them as a truck engine (DF40) and a performance engine (DF50) built on the same block.

 

[Silvertip]

Re: 40hp vs. 50hp engines with the same engine block (suzuki df40/df50)

I have a 2008 DF40 on my Misty Harbor 1880CF and it performs very well. It's comfort zone is 4500 - 4800 rpm with an 11P prop. It will do 21 MPH at 5800 and cruises nicely at 17 - 18 MPH at 4800 so the extra revs on the 50 would likely drink more fuel and provide only an extra 2 mph or so.