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General Aquasport Forums => Aquasport Discussion => Topic started by: chopper on October 08, 2012, 06:10:02 AM

Title: repowering 250 0sprey centerconsole
Post by: chopper on October 08, 2012, 06:10:02 AM
I own a 2000 osprey 250 centerconsole.The boat is in great shape but soon need to repower. It presently has a single yamaha 250. I would like to replace with 2 115 yamaha 4 strokes. Is there someone I could contact that may know if this is possible. The boat is presently in the Bahamas do not have any measurements on the transom. thanks for any help jb.
Title: Re: repowering 250 0sprey centerconsole
Post by: gran398 on October 08, 2012, 07:41:44 AM
Absolutely. it will make a great rig.

Depending on how you use it (weight) you may want to consider stepping up the HP a tad.

See you're in NC, if can be of additional help, will be glad to.
Title: Re: repowering 250 0sprey centerconsole
Post by: seabob4 on October 08, 2012, 08:17:21 AM
Not so fast here boys.  Note the transom cut on Pete's 225, which was identical to the 245/250...

(http://i259.photobucket.com/albums/hh301/seabob4/HPIM0355-1.jpg)

You can see how just inboard of the swim platform the transom cap dips down (see the white plastic trim piece?).  We cut approximately 2" off the transom cap in this area on single installs.  On twins, we simply ground down the putty that squeezed out when the boat was decked, then installed an aluminum L-angle piece over the seam...no cutting.

So one has to determine if the missing section is going to impact the installation of twins.  Maybe not, but it's not as cut and dried as it may appear.  To the best of my knowledge, we never took a yard boat (one that was more or less built on spec) that had been pre-rigged for a single and turned it into a twin...
Title: Re: repowering 250 0sprey centerconsole
Post by: gran398 on October 08, 2012, 10:23:54 AM
Good work Bob.

Another example of "You can't beat a man at his own game."
Title: Re: repowering 250 0sprey centerconsole
Post by: wingtime on October 08, 2012, 10:42:35 AM
So....  Bob your saying the twin engine boats did not have the dip in the transom and it just went straight across.   So that would mean the twin boats used 25" shaft motors that were mounted to the boat 2" higher than the single engine boats motor height.  The 2" cut out allowed a 25" shaft single motor to be mounted 2" lower to allow for the center of the Vee.   So what if he made the cut out a tad bigger and used 20" shaft motors?
Title: Re: repowering 250 0sprey centerconsole
Post by: seabob4 on October 08, 2012, 12:08:41 PM
Bruce,
Good thinking "out of the box there, but...

I would have concerns from both a safety and engine longevity standpoint due to experience running twins on a 245/250 Osprey.  The boat we used to fish quite a bit, the dual station TM, we fished the Palmetto Kiwannis tourney one year.  October.  Forecast was sunny but windy.  Now that tourney was an inshore/offshore type, you had to register one or the other, not both.  We've got a 26' CC, what do you think we're gonna do?

So we head out of New Pass straight west.  3 to 4s, maybe 5s, tight period, beetch of a day to be heading offshore, but it's a tourney.  Well, the water would come up to, at times, halfway up the motor cowlings, wave after wave after wave.  These were 25" shaft Fichts.  Now, drop down to 20" shafts, keeping the cav plate where it's supposed to be, and I'm sure there would be significant water intrusion into the lower pan, either through the seal around the cowling, or through the engine rigging port on the lower pan...

Now granted, most people would have looked at the condition offshore that day and said the hell with it.  But, being that it was a tourney, we were kinda committed.

So just kinda my 2 cents on using 20" shafts in that configuration...
Title: Re: repowering 250 0sprey centerconsole
Post by: wingtime on October 08, 2012, 12:27:09 PM
I meant make the cut out wider not lower.  And 20" shaft would probably be too short anyways.   I can tell you my motor install height is PERFECT.  If you go back and look at how she rides on plane the top of cavitation plate is dry with the surface of the water running just below it.
Title: Re: repowering 250 0sprey centerconsole
Post by: seabob4 on October 08, 2012, 12:57:20 PM
Quote from: "wingtime"
I meant make the cut out wider not lower.  And 20" shaft would probably be too short anyways.   I can tell you my motor install height is PERFECT.  If you go back and look at how she rides on plane the top of cavitation plate is dry with the surface of the water running just below it.

Understood Bruce.  Basically widening the centers to put the cav plate at the proper location.  But we are looking at a 5" shorter motor.  5" is a lot!  Not to mention, the further outboard you move the starboard motor, the more likely you are going to have interference on the steering cylinder.  Can't remember if it's your boat or the 225, there is a molded relief on the inboard side of the swim platform particularly for that exact condition...
Title: Re: repowering 250 0sprey centerconsole
Post by: Aswaff400 on October 09, 2012, 02:11:27 PM
heres a good pic of the splashwell from the 250 osprey with twins at my work:
(http://i10.photobucket.com/albums/a148/recklesabandon727/250%20osprey/IMG_20120514_105830.jpg?t=1349806113)
Title: Re: repowering 250 0sprey centerconsole
Post by: seabob4 on October 09, 2012, 02:23:26 PM
Excellent Aaron!  There's the relief I was talking about, clearance for the steering cylinder when hard over to port...

The 225, now I remember, used a splashwell mount un-balanced cylinder (can't use an auto-pilot with it), so it didn't need the relief...
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