Correct Transom Settings
Kernie Brashier
ratchet style ). When I bought the boat the jack plate was set to its lowest
setting. This setting was actually lower than the factory mount holes. Anyhoo
I got decent top-end, approx 66-68 mph but a slow hole shot. Soooooo, being
the smart thinker that I am I cranked that &%^$*$ jack plate up about
3 inches. What that got me was zero accerlation and horrible top end ( about 30 ) before the prop blew out of the water and the boat wanted to make a hard right
to the beach. So for the past few weeks, I have been adjusting this stupid
plate 1/4 " in different directions trying to ascertain the best mounting
place. As far as I can tell it is about 1 1/8" up from the bottom holes.
Repeated calls to the Skeeter factory were unproductive, and my dealer told me
to buy a new prop from him at $625.00. The engine is a 94 Mariner 175XRI with
a 24 pitch LaserII.
I am not looking for absolute top-end performance. I am more interested in
good hole-shot and on-plane ride without shooting a rooster tail 8 feet
high.
This is my last stop. If anybody has any experience with a manual jack-plate
setting on the skeeter hull, any information would be appreciated. If not,
I might have a jack plate for sale reeeeeeaaaaaaaaal soon.
-thanks
-kernieb
Stanton Truxillo
height. In general, standard transom heights give a compromise between hole shot
and speed; higher gives a bit more speed with less hole shot; lower gives a bit less
speed, with (sometimes!) more hole shot. Raising the engine can't help hole shot.
That's the general stuff. But your boat has a jack plate, which means the prop is
about 6 inches farther back from the transom than stock. Thus you SHOULD be able to
get the motor up a LITTLE BIT higher than stock without losing prop bite: maybe 3/4
to 1 inch or so. But every boat is different, and as you have probably already found
out, going just a LITTLE BIT too high (even 1/4" or so) causes severe ventilation.
It's a tribute to that Laser prop that it bites enough to get on plane at all!
BTW, I am assuming that you know the basics: use full down trim to get on plane, then
slowly trim up until the hull is running clean.
More basics: what rpm were you turning the Laser II with the jack plate down? Both
rpm out of the hole and at top speed would be useful data. Have you read Mercury's
little book on setting up high-perf boats? It's pretty good, and your dealer should
be able to order it.
Final comment: I'd be slow to change props yet; the Laser II is excellent. I've got
a Merc 150 on an 18 foot Hydra-sport center console (it has a 23" transom height and
a cutaway transom like a bass boat). It came with a standard Merc prop. I tried
a Turbo, a Protester, and a High Five before I found the Laser II - it's the best I've
found for that boat. Hole shot is as good as the High Five (0-30 mph in 5.5 sec),
and top speed as good as the Turbo (58 mph light load, 55-56 with 3 aboard and gear
and ice; not bad for a center-console offshore boat, eh?).
Anyway, think about that, and see if it helps. Good luck!
John Duke
愒o buy a new prop from him at $625.00. The engine is a 94 Mariner 175XRI wit
徨 24 pitch LaserII.
WAY TO HIGH PRICED.....
KM富 am not looking for absolute top-end performance. I am more interested in
愜ood hole-shot and on-plane ride without shooting a rooster tail 8 feet
愣igh.
Adjust the jack plate till the cavitation plate is EVEN with the step
on the transom. Then load the boat, full tanks and a second person and
take off.. Running FLAT OUT on plane you should be turning somewhere
around 6000 RPM. If the tach is right and your turning more RPM you
need MORE prop. If it's turning LESS RPM you need LESS prop. I have
heard of people turning a Mercury/Mariner to 6500+ RPM but that scares
the heck out of me. I won't get mine over 6100.
BTW just in case the cavitation plate is the flat plate above the prop.
John
* 1st 1.15b #2317bt * Proud member of P.E.T.A. People for Eating Tasty Animals