350
C.C.
TWIN-MODEL
3T
DE
LUXE
Dry sump lubrication
is
used on the
3T
model. The oil from the tank
is
fed through
a pipe to the pressure side of the oil pump. From there the oil, under pressure,
is
fed to the timing side plain bearing, where
it
is picked up by the crankshaft annular
groove and forced through drilled oilways to the big end assemblies.
It
then issues
from the big ends in the form of an oil fog, which lubricates the internal parts of
he
engine. The pressure
is
regulated by means of a release valve situated in the front
offside crankcase. The valve consists of a piston and spring and, should the oil
pressure become excessive, the piston
is
forced back on
its
spring, allowing surplus
oil to pass through the uncovered hole in the release valve body to the crankcase.
It
will be seen that the strength of the oil pressure release valve spring regulates
the poundage of the oil pressure.
The rocker gear, push rods and tappets, are lubricated by scavenge oil which, after
k,eing used, returns to the crankcase by way of the push rod tubes.
TAPPET ADJUSTMENT
(3T)
Tappet adjustment
is
made on the rocker arms after removing the two tappet
inspection covers on the rocker boxes.
Method of adjustment
is
described in the
Workshop Manual.
CLUTCH
The clutch on the
3T
model has three corked and four steel plates.
All other
details
as
Workshop Manual.
TY
RES
Dunlop recommended tyre pressure for the
3T
model:
Front 16 lbs. Rear 18 lbs.
3T DE LUXE CRANKCASE ASSEMBLY
The lower haif of the
3T
de Luxe engine
is
fundamentally similar to the larger engine
but differs in the construction of the crankshaft assembly and has a white metal
timing side main bearing.
When dismantling the
3T
crankcase assembly the same procedure should be followed
as
for the larger machines. The only difference being that the crankshaft timing
pinion has
a
thread on
its
end portion and may be removed by the use of the ordinary
cam wheel removal tool part number Z.89. Replacing the timing side main bearing
is
a skilled task, and the bearing should
refera ably
be line reamed or broached after
fitting in the crankcase.
It
should be noted that the
fit
of this bearing controls the
oil pressure at the big ends, and if this bearing
is
slack the oil pressure will be low.
To Next Page
Loading...
Need help?
General
