Approx cost and choice for i /O

bgreene · #1 07-30-2018, 03:00 PM

Suggested fresh water cooled I/0 to drop into 23' Sceptre........including outdrive etc complete.

Figure want at least 40 mph top end.

Fr. Frank · #2 07-31-2018, 08:11 AM

The 40 mph top end will cost you up to an extra 4G over a 37-38 mph top end. The Tsunami/Sceptre equipped with the OEM Mercruiser 5.7L 260 hp turning a Alpha drive could achieve 37-38 mph. To get to 40 mph, I figure you need 300-320 hp, assuming the Alpha I/Alpha Gen II drive.
You might achieve 40 mph with 260-270 hp and a Bravo III, or Volvo 290DP drive, because of the increased efficiency of the counter rotating propellers.

A quick look turned up this:
Sterndrives.com (not a recommendation)
5.0L 260 hp with Bravo III complete (no shipping or installation) $11,525
350 Mag MPI (300 hp) with Bravo III complete $14,331
MX 6.2 MPI Horizon (320 hp) with Bravo III complete $17,056

Figure $500-750 for shipping, another $1500 for installation, $1800 for the FW cooling package, and throw in $2000 for incidentals like gauges, monitoring systems, and other unexpected stuff. And this assumes your boat is ready for install.

Islandtrader · #3 07-31-2018, 08:40 AM

Way back when...the cost of my stroker 383 mpi with bravo and 350 hp. Not FWC was approx. 14k. Top speed just over 50. Fuel used at cruise...8-9 gph and that was pushing 25-27 mph.

bgreene · #4 07-31-2018, 07:41 PM

Frank - thanks for all the information you put into your reply - appreciated.

Too bad you can't see how fast I'm running........away from this idea........I may even pass by Usain Bolt !!

dginge · #5 09-08-2018, 08:04 AM

My Yanmar 6LP 250 has a max rpm of 3800. I cruise at 3050ish....32.5 mph to be most efficient. With the bimini top up and plenty of drag I have seen 42 mph. I bet if I tried hard I could get 45 mph. I get 3.8 mpg too. 76 gallons of diesel. Bravo 3 drive with duo. The guys down in mastry told me the replacement engine is well over 40 now for that engine. Uhhhhhhhhh

Fr. Frank · #6 09-09-2018, 10:05 AM

Quote:

Originally Posted by bgreene

Frank - thanks for all the information you put into your reply - appreciated.

Too bad you can't see how fast I'm running........away from this idea........I may even pass by Usain Bolt !!

Were you to choose to put a bracket and outboard on your boat, you're into even more money.

$5K to rebuild the transom. (Only $1800 if you do it yourself)
$3K for a flotation bracket. (Maybe only $1600-1800 used).
$20K for new 25" or 30" 2018 Mercury Verado 300 hp (Dealer cost is around $18.5K. A NOS left-over 2015 300XL is around $17K, and low hours used 2011-2013 300XL can be purchased for around $11K)

Then you've got your installation to do...