Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Preformance enhancements found

Posted by scrimshaw on 05/07/08 - 5:34 AM
#1

Sea trials with my 1971 Outrage 21 and 2006 Optimax 150 have shown marked improvements in fuel effiency ,handling and top end speed with jackplate installed. Day one was spent adjusting engine hieght spinning a Mercury Ventura 19p prop (2 vents open) I saw 46 MPH and a sweet spot at 32 MPH burning 4.8 GPH equaling 6.6 miles per gallon ! I found strange that the boat continued to gain speed without advancing the throttle as the prop continued to grab, I've ordered solid plugs and expect even better preformance without ventilation. Testing with a Laser II 19p achieved 52 MPH at 5500 RPM and will not continue as the entire boat seems to be out of the water except for a few inches aft pushing it any futher is not for me ! It was amazing to see water pressure steady at all heights. It's a good addition in my application.

Edited by scrimshaw on 05/07/08 - 5:44 AM

Posted by Pwhaler on 05/07/08 - 2:08 PM
#2

How much affect did you find the Jack plate to have?

Posted by scrimshaw on 05/07/08 - 2:53 PM
#3

Jackplate has increased miles per gallon , last season per Smartcraft gauges I saw 6 miles per gallon only a couple of times during the season, now I can find it easily, best was 6.6 miles per gallon. The 19p props were difficult to get spinning fast enough without trimming them real high, can find 5500 easily. With the old outrage the engine mounts inside the aft of the boat thus the quaters act as trim tabs and there was little effect with trim now with the engine out back I can raise and lower the bow alittle.

Posted by arthureld on 05/07/08 - 4:37 PM
#4

Jim, what was your top speed before the jackplate?
You are getting 10 mph more than me and it sounds like you aren't even trying for top speed.

Posted by Tom W Clark on 05/07/08 - 5:55 PM
#5

Jim,

There is no reason for you to be running any propeller with vent holes in it. Plug them all; your boat should not have any trouble getting on plane.

Edited by Tom W Clark on 05/07/08 - 9:00 PM

Posted by Yiddil on 05/07/08 - 8:50 PM
#6

Thats quite incredible! Sounds like a sweet ride indeed:) My BEst Henry

Posted by scrimshaw on 05/08/08 - 3:16 AM
#7

Tom, the prop is the one we spoke of in the winter, purchased it for $200 arrived missing 2 plugs, awaiting arrival of solid plugs.

Posted by Binkie on 05/08/08 - 6:45 AM
#8

How much setback does your jackplate have?

Posted by scrimshaw on 05/08/08 - 1:36 PM
#9

Rich, 6 inches, I wasn't comfortable with anything greater as the physics of the setback would increase strain on the 37 year old transom.