I still love my Merc 115 two stroke DFI. Great mileage and a top end of 41mph on my twenty. I also love the quietness of four strokes.

Michael

Hi Capt5245, I have a 71 CC custom open fisherman, and powered it with a Merc 225 Opti. This is a lot of power for this boat, but it will easily handle it, and when I retire this motor I will go with their 250HP Opti. I prefer the bigger motors encase I want to carry a lot of weight in the boat, which puts little to no strain on the motor, and also gives me the extra power and speed if necessary. My boat will run all day, on 25 or so gallons of gas, turning 3000 to 4200 rpm's. My beliefs in motor size is simple, if I need the extra power it's their, and if I under power the boat, I can't. If I were you, I would go with at least a 150HP motor, more likely a 200HP motor, you won't regret it.

I have a F100 on a 1975 20 master angler with a giant T-top. I am happy with it. I think a 115 would be great.

Thank you for the input!

90 optimax on 70's safari, no speed demon but moves 20 to 23 fine. How fast do you need to go?

90's
 

But you run very light don't you?
Like this.......

go with a 150!...i had a yamaha 115 and it has no torque! I went with an e-tech.

ETEC Torque
 

Yes, the ETECs have strong torque, particularly at lower rpm. They win the “tractor-pulls” versus identical hulls. While probably not a problem for most CSC users, my G1 ETEC 150 HO on my 20’ Seafari was too torquey. It would not hold a steady wakeboard speed of about 18mph. The old V6 Merc 150 required some throttle manipulation, but would hold speed. I solved the ETEC issue with a 5 blade High Five prop and a PerfectPass GPS speed control. After spending about $1200 and lots of hours to figure how to adapt it to the ETEC, I have a tow machine that keeps the driver and the rider happy! BTW the ETEC is quick starting and much quieter.

Did you re-power with the Yammie? Just thinking (dangerous, I know), I believe that newer Merc 115 2.1 L would allow you to keep your old controls, and save you a couple grand on the motor price, too. with nearly 20% more displacement, pretty sure it out performs the Yammie and runs only 365 lbs or so. For performance perspective check out Bigshrimpin's performance - he just re-powered his 23 with a late model 150 Merc 4-S and is producing some very impressive numbers. Which ever color you choose, good luck with your purchase - modern motors are sweet!
Here's bit of that thread:
http://www.classicseacraft.com/commu...t=28644&page=3
check his metered performance on page 9.

Thank you! Have not done anything yet. Going to finance the work on the new boat with the proceeds of the sale on the old boat.