Aaaaaaahh ! --- repower w/ an I/O or O/B ????

[abl1111]

I am driving myself nuts ! So, I might as well drive you all a little nuts. For the life of me, I cannot decide on which power to go with - a 300HP, 5.7 litre i/o, or a Yam. 250 HP D.I. o/b on a bracket !!!

There are pros and cons to each ! Does anyone have a 23' Sceptre w/ a 250 on a bracket ? Let me know how she handles, fuel burn, w/ a full load does she get out of the hole well ? What speed/RPM does she cruise at ?

One day I lean to the i/o and then the next I am all for an outboard...

I can probably get into a new, non-current i/o for 11K w/ out harness, gauges, or prop.

The ob I have found is a left over Yamaha 250 HPDI @ 11K ( in the box w/ nothing else ).

The bracket issue seems like it's $$$ and almost a quasi-science to choose and install.

I need to get this decision made now so I can re-do the transom accordingly...

Your imput much appreciated...

[tunsmoor]

I own a 1979 SeaVette that was originally powered with twin 200 hp Evinrudes, mounted on the transom. I had the transom replaced and mounted the O/B's 30" back on a custom bracket. Second smartest thing I ever did. First one was having a professional do the job.
You do not mention what the current powerplant is. I assume it is an I/O. As to your decision, there are pros and cons to both setups. The I/O engine is easy to work on, fuel efficient, and very reliable. If you currently have an I/O, it should be relatively easy to replace the existing components with new ones. The gas tank is designed for an I/O, and your center of gravity will remain the same. In other words- you will not be surprised the first time you take her out. Outdrives have come a long way and many of the problems that plauged them in the past have been corrected. However, they still sit in the water and are subject to all the problems of submersion i.e. corrosion. You do not mention which manufacturer you are looking at. I would recommend Volvo. I own a '69 Donzi with the original outdrive, it has never been rebuilt and I am pushing 300 hp through it. Not one problem ever. I would never own another brand of outdrive.
The outboard is also a good choice. Moving the outboard back 25 to 30 inches will increase the responsiveness to trimming a great deal. Mine was like night and day. Outboards have also come a long way. They are relatively fuel efficient, reliable, and you can tilt it fully out of the water. The downside is that they are very expensive to work on. If you are converting from an I/O, your gas tank might not be large enough to give you the cruising range you would like. Your center of gravity might change also so you may be riding lower in the bow than you used to, no matter how much you try to trim. It may sound trivial, but your towing characteristics will change also. Pushing the motor back that far will give you a lighter tongue weight, requiring adjustments to your trailer. Mine required moving the axles back.
My GPS shows my boat to run at 56 MPH, at 5400 RPM, and I chew about 40 GPH WOT. I have a 126 Gal gas tank.
My recommendation is to stick with what you have. If you have an O/B, you would be wise to redo the transom and add a bracket. Make sure the bracket adds flotation as well. Get the longshaft version of the motor!!
I apologize for the length of this response but it seems you are dumping a lot of money and effort into this project and you want the outcome to meet your expectations. There is no one right answer, you must consider all the factors that are involved. Time and money are the biggest. If you wish to discuss this more I would be happy to. My e-mail is tunsmoor@comcast.net. Good luck!

[Finster]

Alb1111, go with OB/bracket. It will give you ton's more room and storage. And depending on which bracket you go with your boat should sit higher in the water.
It's a little bit of work reconfiging the transom and motor box, but I think in the long run you'll be better off.

Did you put a new transom in yet?

[abl1111]

Hey guys thx for your responses. The boat presently has (2) i/o's - a configuration I do not want. I have not done the transom yet ( still tyring to get rid of the (2) 4 cyl i/o's in there). I have a guy who wants them, but it's taking time to actually get him there to remove them so I can get into the transon area...

I need to make a decision on this motor thing because the transom rebuild is entirely diferent for the two options. I would go w/ an outboard if I knew that the fuel consumption was comparable to the i/o, and if the overall cost was within $3000 of an i/o... I feel that a sinlge o/b would always be straining to move this heavy hull - running at high RPM's. What do you think ?

A bracket is approx $2000, right ? A motor I can get for about 11-12K. Controls, prop, gauges, oil reservoir etc. approx another $1500-2K... It starts to add up - FAST ! I would like to even just see a 23' Tsunami w/ the bracket I have never seen it...

The only things I do not like about the i/o is the outdrives have always seemed like a weak link; always in the water/electrolysis etc.. Motors are loud. They take up cockpit space. The good things are that you can work on it. They are fuel efficient. And the up-front cost seems less...

Hmmmm...

[Finster]

Alb1111, mine is/was twin i/o as well. I went with a Seamark bracket which is more that 2k, I think it's worth it. I am just about finished with the transom at this point.

[ScottM]

Originally posted by abl1111:
I feel that a sinlge o/b would always be straining to move this heavy hull - running at high RPM's. What do you think ?

<font size="2" face="Verdana, Helvetica, sans-serif">A single OB would not be straining to move your boat. With 144 gallons of fuel and 4 guys on board, our Sceptre moves along quite well with the old '89 Rude 225. Cruise is 22 knots at 4000 or 24 knots at 4500, WOT is 32 knots at 5500 turning a 15 X 17 SS 3-blade wheel. With a brand new 225-250 OB (2- or 4-stroke) on your rig, you'd get even better cruise/WOT figures than that. Yeah, a V-6 OB runs at higher RPM than a V-8 inboard, but the OB is not straining in the least bit.

[abl1111]

Chris,

What motor you going w/ ? And, how much does a Hermco bracket go for - dual or single ? How tough is /was the transom to do ? How did you support the transom for the outboard bracket ? Have you ever seen a Sceptre done this way ? Did you re-floor the floor where the i/o motor box was ? Are you doing the work yourself ?

Chris, where you been ??? You are the first guy I know who has done the project I'm going to be doing... I would appreciate any and all info you can provide...

Alan

[Finster]

That's way too many questions, I'll email you my phone number.

[barnacle]

Going the outboard way you will be really close if not over the $3,000.00 mark. We do both kinds of installs and if you walked in we would say go the I/O route. It is much cheaper going that way. I would choose MerCruiser over the Volvo Penta for 2 reasons. First is price and the Second is MerCruiser is using the triple nickle system which is much ahead of the MEFI system that volvo is still using. I can not see the Mercruiser 5.7MPI Horizion with a Bravo 1 drive cost you more then 13,000. with the controls, gauges, harness, and steering system. If you want I can price you a MerCruiser package vrs a 250 Evinrude Di package with a Armstrong bracket.

[Finster]

Joe, you'll redo an i/o transom to o/b with a bracket for 3k??

I'd like to see that.

[ May 14, 2003, 08:56 PM: Message edited by: Finster ]