Flooding From Float Chamber Or Mouth Of Jet; Leakage From Bottom Of Jet; Hints And Tips; The Float Chamber - Triumph SPEED TWIN 1945 Workshop Instruction Manual

S.U.
Carburerrer
I
F L O O D I N G F R O M F L O A T C H A M B E R O R MOUTH O F J E T
Flooding may occur due t o a punctured float, o r t o d i r t between the float chamber
needle valve and its seating. T o remedy either defect, t h e float chamber l i d should
be removed and t h e necessary cleaning, float replacement o r repair effected. T h e
needle and seating u n i t number i s T2, t o identify which t w o r i n g grooves are machined
around t h e seating.
Flooding may also occur i f t h e original manufacturer's setting o f the hinged f o r k lever
(11) i n t h e t o p o f t h e float chamber has been disturbed, possibly causing t h e petrol
level t o be higher than noimal, this higher level giving a slow petrol bleed over t h e
jet bridge. The setting figure f o r this f o r k i s that w i t h t h e f o r k pressing t h e needle
home o n
i t s
seating, a (9.5 mm.) diameter test bar should just slide easily between
the curve o f t h e f o r k and t h e circular facing of the float lid casting.
Flooding may also be caused by a bad seal between the float needle and its seating.
and w h i c h may sometimes be restored by giving the needle a few light taps wyth a
delicate instrument such
as
the handle of a screwdriver.:
R O U G H H A N D L I N G W I L L RENDER THE PARTS SCRAP.
L e a k a g e f r o m b o t t o m o f J e t
If persistent slow leakage i s observed in the neighbourhood of the jet head, it i s
probable t h a t t h e jet gland washer (7) and i t s lower counterpart, together w i t h the
locking screw washer (19) require replacement. The jet lever (23) should f i r s t be
detached f r o m t h e jet head, the locking screw (15) removed, and the entire jet and
jet bush a s s ~ m b l y withdrawn. O n re-assembly, great care should be taken t o
replace all parts i n their correct situations, as shown i n the diagram. Re-centring
of t h e jet, as previously described, w i l l of course be necessary after this operation.
H I N T S A N D T I P S
I
L
These are a few o f the points t o which the Owner should pay particular attention i n
order
to
maintain minimum fuel consumption and maximum power.
1. T h e F l o a t C h a m b e r . If rough running and poor idling are suddenly ex-
perienced, t h e internal float chamber condition
i s
usually responsible. To overcome
this t r o u b l e remove the float chamber every t w o months and thoroug,hly cleali.
W h e n replacing, do not overtighten the lid sleeve nut
as
this w i l l cause distortion
and leakage of fuel
a t
the joint between lid and float chamber.
2.
A i r Leaks. Leakage
a t
the manifold t o engine and carburetter t o manifold
w i l l completely upse: the smooth performance of the engine.
3.
S t i c k i n g Piston.
D i r t , corrosion o r malalignment of the
j e t
w i l l cause the
piston t o stick. Make sure that :he suction chamber w d p i ~ o n are perfectly
d r y
and clean, and that t h e PISTON ROD, which must move freely i n
i t s
bush. IS OILED.
Before attempting t o re-centre the jet t r y the effect of turning
it
through 180'.
11
may have been replaced i n the opposite position, i n the mixture lever.
4.
T h r o t t l e Spindle.
Overstressing the t h r o t t l e spindle torsion return spring
i s
J .
common fault. This causes the coils t o bind before fuil t h r o t t l e
i s
attained, and
disturb t h e whole mechanism. Incorrect ~ o s i t i o n i n g of the moiable throttle le\er
may d o t h e same.