help with motor selection

dearl · #1 07-30-2006, 06:48 PM

I have been doing some book work on my 72 Grady project, trying to plan ahead for the motor install, but I'm stuck on the single or dual outboard delima. My plan is to try and get at least 250 h.p on this transom, its rated for 245 on the tag. I know once I install the 1 1/2 coosa bluewater in her she will hold alittle more. I have given a lot of thought about the weight of the bracket also, most i have seen range from 115-140 lbs. depending on the application. I will stay away from a heavy 4 stroke if i have to, but i don't want to sacrifice eff. and speed tooo much! Right now the boat weighs about 2400 lbs with the inline 6 and OMC outdrive, it is a walk around cuddy cabin, and is built really, really well to accept a bracket. Any Help?

warthog5 · #2 07-30-2006, 09:54 PM

A single DF-250 Suzzy.

dearl · #3 07-30-2006, 10:49 PM

I know you run dual suzzies on the X-SHARK wart, but makes you chose the single 250?

warthog5 · #4 07-31-2006, 12:23 PM

240lbs less weight. I belive the fuel milage may improve more also with the single.

Old'sCool · #5 07-31-2006, 01:28 PM

That would also be my choice. The Suzi runs a larger gearcase, larger dia. prop, and oil bath chain drive camshaft. Both it and tha Yam. 250 4s run variable valve timing but the Yam. has a rubber belt. Just my $.02

oz775 · #6 07-31-2006, 03:26 PM

All the high pressure injection outboards out there right now- Merc Optimax, Yami HPDI, E-TEC, are a lot lighter, cheaper, and get out of the hole faster than a 4 stroke- If you really check the gas milege numbers, the 4 strokes dont beat them by that much- in my mind not enough to spend the extra $$$$.

Bigshrimpin · #7 08-06-2006, 02:55 AM

Dearl - Why not keep it an I/O? It's a four stroke and provides the full transom you desire. If the engine and outdrive work . . . why not keep it?

dearl · #8 08-06-2006, 07:25 PM

To be honest, I have been over this alot with alot of people that have been around boats alot longer than me, and with all that help, i still can't make up my mind.I would consider going to something like the smaller 4.3 V6, but i would want a better drive than a omc. Still up in the air, but i've got plenty of time!

samuelcooper · #9 08-13-2006, 09:53 AM

For what it is worth, I have a good friend who has a 1966 20 ft Bertram which he has had since it was new. For the past 15 or so years, he's been running the 4.3 v6 with mercruiser sterndrive. She runs very sweet, quiet, and uses WAY less fuel than I did with a 130 Johnson pushing an 18 ft, much lighter boat. From what I have heard, the omc sterndrives are close to junk. I don't know what the conversion would cost or even it it is possible. Also, I think if you run in saltwater, a heat exchanger is a necessity.