Quote:
Originally Posted by mrobertson
I know this has been covered alot. Not a speed demon, etc.
Just looking for some insight from guys running 115's on a 20.
I found a smoking deal on a brand new Yamaha 115 2 stroke carb engine. Late model 2007 never been installed leftover. I had my heart set on a Zuke 140 but this deal is half the price.
Just looking for some reassurance that the performance is adequate. I already have a fully restored 23. My 20 is going to be for running around, back bay fishing, etc.
Anyone care to share performance numbers on a 20 SF with a 115 2 stroke?
|
You made a great choice with that 115! I ran my Seafari for 31 years with a 300 lb 1975 115 Evinrude cross-flow motor on it and it was a perfect match for the boat. Back then motors were rated at the powerhead, and it was actually only about 90 hp at the prop! That newer motor should be at least 25 hp stronger than what I used to run! I have trim tabs and a Doelfin on the motor and could plane at 12-13 mph with a very heavy Bahamas type load, ~ 80 gallons of gas, up to 4 scuba tanks, and a couple of big coolers full of ice and groceries. It also had a 2.0:1 gear ratio, and I ran a 13 3/4 x 15"pitch OMC SST prop that was a perfect match for it. You might be able to run a 17" pitch with a lighter boat and a little stronger motor. We used to cruise all day long at 4500 rpm and about about 20 kts (~ 23 mph) at about 8 gph, with zero durability problems. It was still running good with about 1000 hrs on it when I sold it prior to repower with the E-Tec. I seriously considered going with a 115 E-Tec, but the V-4's weren't yet in production in 2006 when I was ready for a motor. I made 6 trips from Palm Beach to the Abaco's (Green Turtle, Great Guana & Man O'War Cays), about 160+nm each way, and I averaged 2.8 mpg over those 6 trips, running heavily loaded each time. The most speed I ever saw with that motor was about 35 with a light load; I could run at least 32 anytime even with a heavy load. Don't know much about those Yamaha's, but from what I've seen they appear to be pretty much copies of the newer OMC's. I'm sure it's loop charged, which should help fuel burn. On that lighter boat, I'd think you would easily get 3 mpg and maybe 37-38 mph WOT with a good stainless prop. (I think Gillie would get a little better mpg if he ran a stainless prop!) Motor should be set up with AV plate at least 1" above the keel.