Twin Yamaha F115s on a bracketted 23'?

CMBarnes · #1 05-25-2010, 12:22 PM

It's been a long time since I have posted on here. I have a fully restored 1975 23' that had twin 200 Mercury EFIs. I have sold those motors as they needed some work and have an opportunity to get 2 4-stroke yamaha 115s for a good price. The weight on the engines is the same as the 200s but I know the top end speed would be way down (Although fuel efficiency would be much improved). I have researched and am guessing low 40s mph wot (Down from 60+). I am concerned with resale value as I am looking to sell the boat. The other options are selling motor-less or reconfiguring the bracket and putting a 30" F250 yamaha, which would cost me more. Any thoughts are appreciated....

Thanks,

CMBarnes

ricknewman · #2 05-25-2010, 01:31 PM

My personal opinion is that the boat would be more desirable with the single 250. I would think it would cost less than 2 115's and can you use the same bracket? But, trying to sell a boat in this market I doubt that you would recoup the expense of re-rigging so you may be better off selling the hull and trailer.

Capt Chuck · #3 05-25-2010, 01:55 PM

Hi Chris, it has been awhile (4 years)

You cannot plane the 23' on one 115hp motor should you loose one. I think twin 115hp are to small and not enough torque to get the performance you would want out of that hull.

PS: Remember you will have to go with a 30" single motor on a twin bracket.

Hope all is well

CMBarnes · #4 05-25-2010, 03:28 PM

Thanks for the replies. Capt. Chuck, it is good to hear from you. It has been too long. I have been good but have not been using the boat like she deserves. I went back to school and got a degree in yacht design up in Maine and went to work for Scout Boats as a product/design engineer. I am now with another company but still working with boats. The seacraft bug has grown into a career path.

The deal on the 115s is a good one and they will be cheaper than a single engine. The bracket is ready for them as is and the steering and power is already run. My boat wouldn't plane off with one 200 so that isn't a huge issue to me (not propped for that). You would still be able to make it home with a single 115. I can do some of the rigging myself and have a buddy from Scout to help out as well. I can also get good pricing on the yamaha binnacle, props, throttle cable, gauges, ect...

I am having trouble finding a single 30" F250 and yamaha is what sells around here. Also, I would have to have some welding done on the bracket and fill holes in the dash for gauges. Do you guys think I would be better off just listing the hull and trailer or re-powering with these F115s??

Thanks Again!!

travisrandall · #5 05-25-2010, 06:47 PM

Are you near Charleston?

CMBarnes · #6 05-25-2010, 07:37 PM

I am in Charleston. Any thoughts on my situation??

Old'sCool · #7 05-25-2010, 08:18 PM

I dont think thats enough HP and I dont think you would be happy with it. I'm in Chas also. My '73 23' has alum bracket and 250 OX66 Yam. Somedays I wish it were two

travisrandall · #8 05-25-2010, 11:35 PM

im thinking it would be nice to have twins, looking at v-6 merc 135's but im not willing to drop 3500 for a new bracket. its nice offshore with twins, but you never know what can happen. how is scout doing lately? nice gauge for local economy. went out sunday in a 27 rabco and couldn't plane out with one 225 efi. lost the lower unit in the other, so having the right spare prop makes a huge difference.

Fr. Frank · #9 05-26-2010, 01:24 AM

Having the right spare propeller in an emergency is important.

The Town of Palm Beach used to have a 23' SF as a patrol boat, rigged with twin RH rotation Evinrude 235's. It would not plane on a single engine with the normal 27"P props. But we put a single 17"P stainless prop on board as a spare. More than once, it came home using the spare prop on a single running or intact engine, and it came in on plane with the other motor tilted up. When those motors were replaced with CR 150 hp 'Rudes, I was told they could still get on plane with a single engine, trim tabs, and a low pitch prop.

A 23' will NOT plane, however, with a single offset 115 hp motor.

Briguy · #10 05-31-2010, 07:05 PM

I beg to argue Chuck. My 1978 CC with a bracket will plane with a single 115 and that's swinging a 24" ss Suzi prop. You need tabs down, 1 motor tilted slightly and at 4400 rpm's she'll make 14 1/2 knots.

The 115's will make 25.5kts at 4000 rpm's and 39kts at 5950 rpm's. with 3/4 fuel and 2 people. If you have 6 people and lots of ice I see 25kts at 4300 rpms and fast cruise of 32kts at 5k rpm's.......and that's on 9 year old Suzi's!!!!!!!!!