questions for the 19-6 owners

[tmyers]

I have a 72' 19-6 with a F115.   The boat used to be an i/O.  The boat cruises best at 4K around 20knts. With my 19 pitch WOT is around 5600 and 28-29 knts.  With the 17 pitch 5900 and about the same WOT.  However, cruisiing rpm is around 4300 and does not like to criuses @3500-3600 strugglinig plaining.
My first thought is that the stringers may be water logged and will be puting a water meter up the them to check.  I alos do have a T-top which will cause some drag.  It seems to me that I should be WOT around the  40mph range with the F115.
I am curios to know what members are running motor wise and speed with thier 19-6.
Another question would be does that fact the boat being an old I/O hull have more deadrise to make a slower hull?
Thanks!

[fitz73222]

If its an original 72 there is no doubt she is carrying some extra weight but something is wrong with your numbers. How are you measuring speed? What is your engine gear ratio? I have a formula we can use to mathematically calculate your speed. You should be in the +/-40 mph range.

[tmyers]

Measuring speed with GPS.  I will change it to MPH
Gear ratio?  Will have to look.

[gran398]

Fitz is correct, pretty much any original 70's Aquasport is holding water. An easy way to tell how much extra weight....take everything to some truck scales, then afterward weigh the truck only.

The hull is the same twelve degree deadrise regardless of I/O or outboard. Is the transom open, or was a bracket added?

Agree...you should be somewhere around 39-40 WOT with light load.

[tmyers]

I will try and get a wieght also.
The  transom is a full transom wit a cap.  The motor is on a paralift.
Thanks guys for your help.

[Aswaff400]

my 200 osprey with a old 112hp johnson ran around 39-40 mph 55-5700rpm and cruised mid-upper 20's 4000rpm, with the 200hp evinrude, she'd run low-mid 50's turning 50-5500rpm(depending on prop) and cruised 30-35 mph at 3500 rpm depending on prop...

no doubt your stringers and foam outside of the stringers is water logged, i dug probably 700 lbs of saturated foam out of my flatback's stingers

[MarshMarlowe196]

A member here named fishcole08 had the same engine on his 77' 19-6, and ran 42mph with a 17" pitch. He since sold the boat to another member here named "david.". -

viewtopic.php?f=2&t=8887&hilit=fishcole

The stringers in my 73' are pretty dry last time I checked, but my boat lived in a garage almost year round and saw very little use. I cut a hatch in the floor @ the stern to install some bilge pumps, and checked the dampness of my stringers while I was at it via a 1/2" hole drilled on either side. Patched the holes up after I was satisfied. Might be something to try.

FWIW, I run 42mph w/ a DF140. Boat planes out quickly.

[classic19'6]

Hmm something is definitely not right...

I run a 75hp Merc and it pushes my 72' 19'6 right around 32mph!

[tmyers]

Well went and weighed the boat.  
Boat trailer and motor =3500 lbs
trailer and motor =900 lbs
Boat = 2600 lbs
boat has T-top, 20 gals fuel, gear and 4 batteries.
i'd say the boat has a few hundred lbs of water wieght.
I 'm going to have my 19 pitch prop checked out and see if it needs to be refubished and then maybe pick a a few mph.
Thanks again everyone.