yamaha F115
 

Looking to repower a 20ft MA. I want to repower with a 4 stroke and was wondering if a 115hp would work. Do you think it will be slugish with 3people? I know a 150 would work but I found a good deal on a 115hp. thoughts?

Re: yamaha F115
 

Fr. Frank seems VERY happy with a Merc 90HP on his Seafari. I'm sure he'll chime in on the subject.

Re: yamaha F115
 

Those motors although very reliable are not the strongest horse in the barn - would be woefully under peowered. When new we never rigged any with less than the inline Merc 150's and they don't stack up to modern 2 strokes. It may be a good deal, I just don't think for you. Its not based on top speed, its handling at mid range to keep the boat up on top - drive-ability. It will suck fuel too, 4 strokes are not any better near wide open, their all hungry.
JMHO

Re: yamaha F115
 

I had a 115 Everdog 2 stroke on mine and was never happy. The fuel burn was good but on those few nice days when you can turn her loose it left you wanting.

Re: yamaha F115
 

Thanks for the imput. I just found fund a good deal on a yamaha
130hp 2 stroke with low hrs. Im thinking that should work fine.

Re: yamaha F115
 

Ye, I love my 5+ mile to the gallon with my 90 hp Optimax on my 20' Seafari. WOT mid-low 30's.

But I confess their are days I really miss pushing the boat past 50 mph like I could with the old V6 Merc.

The 130 Yamaha 2S may be just right. I love those "Tower of Power" 140/150 I6 Mercs, though.

Re: yamaha F115
 

would work much better, even a V6 150 Merc is pretty light too

Re: yamaha F115
 

I have a F115 on my 20' '71 seacraft and love it...3 people, 60 gallons gas, offshore fishing gear, ice ect...we cruise 27kts @ 4500 rpm...average gas mpg is 4.5miles/gallon...wot w/ 20 gallons, 2people is 38kts @5900 rpm...

Re: yamaha F115
 

Those are excellent numbers, although I have the same boat with a fresh 200 merc and you couldn't pay me to run it with less than 150 but I guess thats me.
Second reason, I wouldn't consider buying one with only 115 - I wouldn't want to try and sell one either and deal with the constant "Seems unpowered" question a million times. These are pretty high permance hulls and need HP to work properly, but your happy with yours and it seems by those numbers very close to my 200, thats strong for a 115- I'm at 3800 to get 27kts I think thats about 31/32.

Re: yamaha F115
 

I have this set up on a shorter bracket. Boat will run 37 knots top end 6100 RPM. Cruise @4000 RPM at 23 knots and only burn 5 gallons an hour. Haven't tried to plane on one engine, but for range and fuel burn she's set up perfectly. if you want specifics let me know.