repower for 1977 20' CC

[Normagain]

I have an 06 Yamaha F115. Here are some numbers with a Solas Amita three blade aluminum 15 pitch prop with 40 gallons of fuel, 45 gallons of water and just me. When fairly lightly loaded it has good power and great economy, was averaging about 4.5mpg. I have a large fuel tank and when I had 1 passenger, 60 gallons of fuel, 45 gallons of water and 80lbs of ice last weekend out of Mission Bay, I was lucky to see 3.4mpg and the boat was pretty sluggish. I still was able to make 20mph at maybe 4500rpms.

I would go Suzuki DF140 if your going new. I was lucky enough to find the F115 used earlier this year or that is what I was getting. I do wish I had the power for those long San Diego runs, but mainly for fuel economy!

rpm mph
700 2.7
1000 4.1mph
1500 5.3
2000 6.7
2500 7.9
3000 9.2
3500 14
4000 20
4500 26
5000 30
5800 35