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 Looking
For The Right Prop
by
Steve Horsfall
We have a 1997 Bayliner
Capri 1700 LS with a Force 120 out-board. For watersports we run
a 16 pitch stainless prop. I tried wakeboarding a few years ago
and I’m hooked. At 22 mph I can clear the wake on my board, but
I can never get more than 2 1/2 feet of air. My friend said with
his boat the slower you go the bigger the wake is, but if we go
slower the wake is smaller. How can I get a bigger wake without
adversely affecting performance?
D. Degenhardt e-mail
Raising the bow or lowering the stern will give
you a bigger wake. To do this you could move weight in your boat
aft or raise the engine angle using power trim. You may want to
go to a higher tilt pin hole, if the engine is not equipped with
power trim. I suggest you try one hole at a time and test. This
will increase wake size, but adversely affect performance and cause
cavitation if raised too high. It will also cause the boat to porpoise
if run at planing speeds. You must lower the engine tilt for normal
use.
Where there’s smoke...
I would appreciate your input on a problem I have with a 1997
Johnson 115hp outboard. A while after I bought it I complained about
excessive smoke from the motor. The dealer replaced the fuel pump
thinking that oil volume coming to the motor might be too much.
This did not solve the problem. I then switched to synthetic oil
by OMC. This also did not solve the problem. This problem only occurs
at start up and at slow cruising speed. I would appreciate your
input.
D. Hammond e-mail
There are a couple of things that may be wrong.
One problem could be the oil blend unit is metering too much oil
into the gas. This may need to be adjusted or replaced. The second
is the fuel mixture is too rich and may require smaller idle jets
or a slight lean out of fuel mixture. The third possibility is that
the situation is normal. I say this because the oil blend system
is a variable ratio setup. When the engine is running at high speed,
it mixes more oil with the gas than it does at idle. However, when
you slow down or shut off after running fast, the carbs are still
full of the rich oil/gas mixture and so there is more smoke until
the leaner idle mixture starts to arrive from the blend pump and
refill the carbs. It may take some time for the oil mixture to stabilize
at the leaner mixture as the engine uses so little fuel at idle.
I would try running the engine for idle at 10-15 minutes and see
if the smoke clears up or at least lessens before seeking any service
on this. (Top)
Gasket kit needed...
We have a ‘51 Johnson 5 hp motor in need of a carburetor kit/gaskets.
We are wondering if you know where or if such a thing is available.
M. McCullough e-mail
Most of the time when I worked on really old motors,
I was frustrated by the lack of parts. Things like gaskets, we usually
made from bulk gasket material. Other parts we tried to adapt from
newer similar parts. You may want to contact Millar-Potter Boat
Restorations in Manotick, ON. Millar-Potter is a wooden boat restoration
shop, but Mr. Potter is a tremendously knowledgeable individual
with a lot of contacts in this field and will most likely be able
to point you in the right direction. Their phone number is (613)
692-3455. Another source may be the Manotick Antique and Classic
Boat Club. You can contact them at P.O. Box 948 Manotick, ON, K0A
2N0.
For a quieter ride....
In the past I have read several of your articles and realized
you have quite a bit of understanding and knowledge on a particular
topic, which I am only learning about. I have a boat in which my
engine box is made of plywood and houses a 289 hp Mercury engine.
The top of the box is a 3x3-foot cushion. You have written about
Styrofoam and spray foam being available for noise reduction. What
would be the best to suit my needs? Is this product heat resistant
as well? Could you please recommend a brand name and a place where
I can purchase it? I would also need instructions as to how I may
apply or install the product.
H. Strombols e-mail
My favourite sound deadening material is a product
called Dynamat and it is available in regular and high heat versions.
It is a self-stick modified polymer sheet that is a very effective
sound deadener. The high heat version has an aluminum foil liner.
It is available from Eastwood Co, Box 3014, Malvern, 19355-0714.
You can fax them at (610) 820-9042 and their Web site is located
at www.eastwoodco.com. This stuff is not cheap, but it is good.
The spray foams are ideal for hard to get places away from engine
heat. (Top)
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