Evinrude 4906B 4HP 1969, Owner'S Manual

Page: 133 / 422

4-42 FUEL
7- Align the mark on the cover with the
mark on the body, and then secure the cover
in this position with the three attaching
screws.
8- Clean the surface of the intake mani-
fold thoroughly. Check to be sure all old
gasket material has been removed. Place a
NEW gasket over the studs and into place on
the manifold. Slide the carburetor onto the
intake manifold studs and secure it in place
with the attaching nuts. Tighten the nuts
EVENLY and ALTERNATELY. Connect the
fuel hose to the carburetor. Connect the
vacuum and water hoses to the carburetor
paying careful ATTENTION to connect the
proper hose to the correct fitting according
to the identification given to the hoses
during disassembly. If identification was
not made during disassemby, follow the hose
to the other end to ensure proper connection
to the carburetor.
a- Connect the water hose to the top
fitting of the water choke.
b-
Connect the outlet water hose to the
fitting closest to the carburetor. The other
end of this line is connected to a fitting on
the exhaust chamber on the port side of the
engine.
c- Connect the vacuum line to the vacu-
um diaphragm fitting. The other end of this
line is connected to the intake manifold.
If the hoses are not connected correctly,
wa ter will be injected into the cylinder
when the engine is cranked, resulting in a
ser ies of horrendous problems.
Install the starter motor and generator if
the engine being serviced is equipped with
these two units. Now, perform the proce-
dures outlined in the next paragraphs to test
and make the carburetor adjustments under
a load condition.
TYPE
n
CARBURETOR ADJUSTMENTS
GOOD WORD
Under all conditions, the ignition and
fuel system MUST be synchronized before
the fine adjustments to the carburetor are
made. See Chapter 5. After the synchroni-
zation has been completed, proceed with the
following work.
9- Mount the engine in a test tank or
body of water. If this is not possible,
connect a flush attachment and garden hose
to the lower unit. ONLY the low-speed
adjustment may be made using the flush
attachment. If the engine is operated above
idle speed with no load on the propeller, the
engine could RUN-AWAY resulting in seri-
ous damage or destruction of the unit.
CAUTION: Water must circulate through
the lower unit to the engine any time the en-
gine is run to prevent
damage to the water
pump in the lower unit. Just five seconds
without water will damage the water pump.
Start the engine and allow it to warm to
operating temperature. Adjust the 10w-
speed idle by turning the low-speed needle
valve CLOCKW1SE until the engine begins to
misfire
or the rpm drops noticeably. From
this point, rotate the needle valve COUNT-
ERCLOCKWISE until the engine is operating
at the highest rpm. .
If the engine is equipped with an adjust-
able high-speed needle valve, shift the
engine into FOR WARD gear, and then ad-
vance the throttle to the wide open position
(WOT). NEVER attempt to make this ad-
justment with a flush attachment and gar-
den hose attached to the lower unit. Adjust
the high-speed by rotating the high-speed
needle valve CLOCKWISE until the number
of rpm begins to drop, then rotate the high-
speed needle valve COUNTER-CLOCKWISE
until the highest rpm is reached. Return the
throttle to idle speed. Adjust the idle speed -
a second time as described earlier in this
step. Again, advance the throttle to the
WOT position and check the high-speed ad-