Weber Carburator Manual.pdf - Power by BMW E21

11-12 Part 2 Weber carburet ors Chapter 11
Fig. 11 .17 M ethod of inserting th e
lead plugs (Sec 6 )
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7.4a Inserting th e th rottle spindle return
spring and accelerato r pump leve r
•
7.4b Fitting th e throttle spindle
7.5 Fitt ing a spi ndle bearin g 7.6 Fitting a throttle spindle dust cover Fig. 11 .18 Thr ottle spindle nut tightening
tool (Sec 7)
overhaul to remove any swarf and dirt, pr eferably using clean
fuel and air pressure. The lead plugs should be renewed and
retained in position by using the Weber too l no 98 0 10 800 as a
punch until the plug is exp anded into its bore.
7 A ssembly
Not e : All com ponents should be clean and dry before srarting
the assembly procedure.
1 If a new spindle (4 1) or pump control lever (35) is being
fitted, first assemb le the laver to th e spindle to ascertain it s fit . If
th e lever is too tight, use a 11 in expanding reerner to enlarge,the
lever bore unt il the spindle is a fi rm sliding fit.
2 Fit one ball-bearing (38) to t he thro ttle spindle (41) by
placing the bearing on an open vice and gently tapping the
spindle into it.
3 Fit the remain ing ball-be aring (3 8) into the carburettor body
using a plastic hammer and suitable diameter tub ing on t he
outer race.
4 Insert th e pump contro l lever (3 5) with spring (3 3 )
assembled , into the carburettcr body. then press the throttle
spindle (41) through the locating bore at the same time entering
it th rough the pump contro l lever (3 5). making sure that the
lever is facing inwa rds (photo s).
5 Tap the spindle bearing (38) into the carburettor body and
check that the opposite bearing has not been displaced (photo).
6 Smear a little grease over the spindle bearings (38). then fi t
the dust covers (16) using a suitable diameter tube to ensure
they are correctly seat ed (photo).
7 Assemble the springs (17). spring covers (18), lever (19).
wa sher (58) and tab w ashers (27) to their respecti ve ends of the
spindle (41 ), then screw on the nuts (2 8) finge r tight.
S Screw the throttle adjust ing screw (21 ) and spring (20) into
the carbureltor body, th en tighten the nut s (28 ) onto the spindle
(41). Use the special Weber too l no 98023 700 to do thi s. but if
not available, tighten the nuts just suff icient to hold the washer
(58) and lever (19) firmly on the spind le (41).
9 Lock the nuts (28) by bending the locktabs (27) (photo).
10 W it h t he throttle spindle (41l in the open posit ion, fit the
throttle valves (40) into t heir location slots then close the
spindle to allow t he valves to centra lise within th e barrels. M ake
sure that the valves (4 0) are fitted the correct w ay round so t hat
t he angled perim eters seat on t he bore.
11 Wit h t he throttle spindle (41) held closed, insert the va lve
retaining screws (39) and tighten them evenly but with out
exerting excessive pressure on th e spindle. It is recommended
that new screws are alwa ys fi tte d as it is quite easy to crossthre
ad previously peened screws. l ock the screw s (3 9) by
peening w ith Weber tool no 98010 900 or alternat ively. by
coating the th reads with a liquid locking agent (fu el resistant )
prior to insert ing th em.
12 If a new pu mp lever (35) or spind le (41) has been fi tt ed, it
w ill be necessary to drill th em in order to fit the fixin g pin (34).
This can be carried out by one of two meth ods. First by using
t he gauge no 98015 600 and spacer no 98007 800 and drilling
the lever and spind le whilst holdi ng the throttle valves shut.
Secondly by fitting the pum p rod and piston assembl y as
described in paragraph 32 , then retaining the rod w it h a bull dog
clamp so that the distance f rom the face of the carburettor body
to the underside of t he pump rod arch is equal to the pum p
stro ke. By closing the th rottle valves and holding the lever (3 5)
against th e pump rod (54) th e spindle can be drilled using a 2 ·0
mm or no 4 6 drill.
13 Drive in t he fixing pin (3 4) using a suita ble punch (photo).
14 Wi th a pair of long nose plie rs, grip the spindle return spring
(33). lift It out of the cerburettcr body , insert the anchoring plate
(32) and locate the pla te in it s location recess (photo).
15 Check that the spindle operates smoo thly, Indicati ng that
the bearings are not binding. If th ere is any ten dency to bind ,
the bearings may not be properly aligned. This may be recti fied
by gent ly tapping th e carb urettor body in t heir vicini ty.