Page 1 of 2

Whats the top end of your Mac when motoring?

Posted: Sun Apr 24, 2005 11:47 am
by moonie
I managed to reach 14.9mph with a full ballast tank and my 50 Etec in a Force 3. I would like to find out if a higher topend is possible with the 50hp.

Posted: Sun Apr 24, 2005 5:48 pm
by baldbaby2000
With my 40hp Tohatsu I can hit almost 14 mph without ballast.

Posted: Sun Apr 24, 2005 9:26 pm
by Rolf
I've done 20 knots (about 24 mph) ballast full with my Tohatsu TLDI 90 horse.
Rolf

Posted: Sun Apr 24, 2005 9:30 pm
by KRV
I cruise at 17 Knots and top out at 20. 70 HP SUZUKI (04 M) with empty ballast.

Posted: Mon Apr 25, 2005 6:58 am
by Norm
20.1mph 26X empty ballast 50hp Johnson 4-stroke, 11.75" 10 pitch prop. No wind, calm lake.

Posted: Mon Apr 25, 2005 7:20 am
by Tom Root
18 MPH top with several hundred pounds of gear, 2 people. One person mostly stipped but mast still on I recently maintained 20 MPH, Ocean, 1-2 foot mini swells, no ballast, Suzuki-50, 10X12 piranha modular composite prop that has been shaved a bit for speed. Love this prop, and would highly recommend it to anyone, so far it has given me many hundreds of miles of great service. Also have two spares....Justin Case! 8) http://www.piranha.com/propellers.php

I am certain, if I remove the mast and extra anchors/chain rhodes etc. I can easily see 22+ MPH on this boat!

Posted: Mon Apr 25, 2005 1:20 pm
by Harrison
Light gear, no mast, 3 adults, no balast, 5400 feet above sea level, Merc 60 BF, calm lake, 5700 RPM, = 18 MPH.

Posted: Mon Apr 25, 2005 7:04 pm
by TampaMac
No mast, no rigging, 60 hp Mercury 4 stroke.

I can't remember the exact figure but it was about 23 mph.

Posted: Mon Apr 25, 2005 7:34 pm
by Steve
I've topped out at 19 w/o full ballast, 14 w/ full ballast, Yamaha 50/4 stroke. Also have a 26 gal. Plastimo water bag under the fore settee at table which I'm sure effects my top end too! :)

:macx:

Posted: Mon Apr 25, 2005 7:41 pm
by Ben
No Ballast, Mast up just under 20mph at 6200rpm on Johnson 50 4 stroke.

Posted: Tue Apr 26, 2005 9:53 pm
by Tom Spohn
Moved the boat today. '04M with 70 HP Suzuki. Two adults, one dog, medium gear, no ballast, topped out at 20.3 mph at 5150 rpm.

KRV What is your max rpm for 20mph and cruise at 17mph?

Posted: Tue Apr 26, 2005 11:19 pm
by awolfe
Moved our boat to her new slip, about 40 miles away. Hit a top speed (w/o ballast, mast down)of 65mph, averaged abouit 55mph - Ford V8. 8)

about 18

Posted: Wed Apr 27, 2005 5:18 am
by Andy26M
2004 26M, no ballast, one person (200#), couple hundred pounds of gear, 20 gallons of water under the V-berth, 50 HP Honda, 24 gallons fuel in the cockpit, mast up, ablative bottom paint:

w.o.t. = 17 mph
= 18 mph if you get rid of the water forward and half the gas

In heavier seas I pump out the V-berth water if I want to go "fast" because it holds the bow down, which is nice for seakeeping but adds more spray in the cockpit.

I'm figuring that the bottom paint (very rough chalky surface) is costing me about 2 mph, but seaweed and barnacles would be even slower...

- AndyS

Posted: Wed Apr 27, 2005 5:57 am
by bobmonroe
While waiting for a 14Dx11p from WM, for my 50ETEC, I decided to try a 3 blade SS, 13Dx17P off my 70 Johnson 17' runabout. The boat was empty, except for 2 adults, 2 -6 packs to keep the waters smooth, and about 12 gal of gas. We did 22.5 statute at 5100 rpm. Later found a new 3 blade alum 14Dx13P at a flea mkt, the boat did 21 mph statute at 5700 rpm. I put 10 gal of water in the bow. I think I need some way to trim the bow down without adding wt. up there. I haven't researched the wedge solution.

engine mount trim

Posted: Wed Apr 27, 2005 11:36 am
by Andy26M
Bobmonroe -

You can effect the trim of the boat to some extent by moving the long pin in the engine mount that the engine sits down on when lowered. There should be a range of holes there in an arc. Putting the pin in a hole closer to the transom should help push the nose down a bit, and vice versa.

- AndyS