BMW Service Bulletin Archive

cv-carbs-571-316-1171

SERVIINCFEO RMATIO\\ -‘l’ocih, C us t. V3-201 โ€ข Service Gi/Zr Motorcycle R 75/5 Munich~ N:bv7. 1 l-_I Ref,: Vacuumtype carburetor Gentlemen, At our mode’ ls R 75/5 ex chassis No. 2 977 320 we install’ vacuum type carburetors with the designation 64/32/9′ ‘r ยท.~ (left) and 64/32/10 (right), The idle system works inde,-ยท pendently from the needle system through lifting of the . lower final position of the diap_hragm and the alteration of the by-pass-bore. The bore of the idle nozzle has been, enlarged and the needle nozzle throughput has been reduced, With the new carburetor the i-dle adjustment and, also the:. starting performance has been considerably improved. , i: . Here are the details about former and’improved carburetdr version: name ~arb. left side ‘carb. right side main nozzle needle jet sealing of mixture tube idle speed nozzle former version 64/32/3 64/32/4 140 2,73 by thread 45 44-966 ยท.,’ :,;, improved tjrsion 64/32/9 โ€ข; 64/32/10 135 2,70 with 0-rir;g .โ€ข 45 44-950 ยท ( (with pre-calibration) (without pre.:.9alioration) โ€ข โ€ข L Kennlnls genommen โ€ข Pris connalssance โ€ข Noted โ€ข Tomado nota โ€ข Preso conoscenza Ablage โ€ข Archives , FIi~ โ€ข Archlvo Betr!ebs1eitung Direction Management f’li,,,,-,.;A~ Werkstall Atelier Workshop T,-,Hn, KO-Annahme GewOhrl.-Saehb. E-Telldlenst Belrlebsleltung Werk$’1ot1 IMcepllon cllent81e lnspecteur gorantfe Service pieces d6taeh6es Direction Ateller ~~!~!?,’:e_P!i,’?_”_,_,_ ~~~r_a_~1Jyn spec_i_or ~par~ parts service Management workshop .{~.:. โ€ข ‘ I II ;,,.:f, : ยท:-. .1.: nar.ie by-pass bore idle mixture screw float needle sprint limitation of diaphragm starter cup ventilation mixture bore in rotary valv” horizontal bore in starter dip tube part carb. left side carb, right side main nozzle needle jet idle speed nozzle – 2 – former version 0,7 6,2 from axle centre 1,0 – 1,5 revolution 10 p O mm 2,0 to outside 2,0 former version 13 11 1 253 858 13 11 1 253 857 13 11 1 254 733 13 11 1 257 772 13 11 1 257 775 improved 1,0 5,3 from axle cent 0,5 – 1,0 revoluti 30 p 6,5 mm 2,0 to inside 2,0-1,2-0,7 14 mm from below improved version 13 11 1 256 73, 13 11 1 256 73 13 11 1 256 61 13 11 1 257 81 13 11 1 257 B~p At the same time with the ‘improved carburetor we have also altered the starter carburetor in.such a way that you can select with the starter lever beside of full-start also intermediate positi.ons for a lower rpm to warm up the engine, Thia is obtained by 3 different sized fuel .feed bores in the rotary valve, so the most favorable fuel quantity depending from the engine temperature can be adjusted, The mixture compound is controlled by a crescent shaped air slot in the rotary valve. The new starter carburetor housing has no more a return spring; ,the choke is activated throush a cable line, The starting process described on page 11 of the owner’s manu~ is now changed as following: S~arting or R 75/5 at cold engine and outside temperature above 0 C is effected by pulling up the choke at closed throttle SSiP and then actuate starter. At outside temperatures below O ยทca raster starting is possible by easy turning on the throttlE after the first series or ignition, – 3 – f ~ S.I. 5/71 (31F) e. – 3 – [tartl~g with kick starter is done in the same way, only ยท.โ€ข:he;; the enr;ine does not start after the first series of !rn’tinns, assist by slirhtly cpened the throttle, As a r~l the eneine has to be in vertical position to avoid differert strong enrichment of the fuel starting mechanism. Yours very truly, BAYERISCHE MOTOREN WERKE Aktieneesellschaft Service Division ppa. l ~ โ€ข. lfr (

About the Service Bulletin Archive

Searchable index of BMW service bulletins for repair and parts installation for a variety of 247 models. This is not an exhaustive list. If you have ones to share to help complete the archive, please contact us directly.