24 and 28mm carburettors are used in Fiat 500’s and Fiat 126’s. These carburettors are used on 600 and 650cc engines. We have tried to make a complete list of all types with their specifications. You can always comment on this page if you are missing something or in case of any mistakes.
24IMB1 #
| Used on | 500R 594cc 1973 126A 5000 |
| Main | 1.25 |
| Stationair | 0.50 |
| Emulsion | F8 |
| Air correct | 2.25 |
| Starter | F5/90 |
| Needle | 1.25 |
| Venturi | 4-18 |
28IMB1-100 #
| Used on | Fiat 500R / Fiat 126 594cc until 11-1974 |
| Main | 1.25 |
| Stationair | 0.45 |
| Emulsion | F8 |
| Air correct | 2.15 |
| Starter | 0.90 |
| Needle | 1.25 |
| Venturi | 4-23 |
Extra info #
- Mixing screw needs spring, saucer and underlying o-ring
- On carburettor Made in Italy
- Top cover often only Weber Logo
Pictures #
28IMB3-100 #
| Used on | Fiat 126 600cc after 11-1974 (Europe 75) |
| Main | 1.25 |
| Stationair | 0.45 |
| Emulsion | F8 |
| Air correct | 2.15 |
| Starter | 0.90 |
| Needle | 1.25 |
| Venturi | 4-23 |
Extra info #
- Mixing screw internal in sleeve and internal o-ring
28IMB3-250 #
| Used on | Fiat 126 594cc 1976 Europe / Fiat 126P 600cc |
| Main | 1.15 |
| Stationair | 0.45 |
| Emulsion | F8 |
| Air correct | 2.15 |
| Starter | 0.90 |
| Needle | 1.25 |
| Venturi | 4-23 |
Extra info #
- Mixing screw internal in sleeve and internal o-ring
- On carburettor Made in Italy, also on top cover
Pictures #
28IMB4-250 #
| Used on | Fiat 126 650cc 1976 (Germany, square head) |
| Main | 1.25 |
| Stationair | 0.45 |
| Emulsion | |
| Air correct | 220 |
| Starter | 0.90 |
| Needle | |
| Venturi | 4-23 |
Extra info #
- Throttle valve has only 1 seal
Pictures #
28IMB5-250 #
| Used on | Fiat 126 1977 until 05-1985 650cc Fiat 4381128 |
| Main | 115 |
| Stationair | 0.50 |
| Emulsion | F8 |
| Air correct | 190 |
| Starter | F5/90 |
| Needle | 1.25 |
| Venturi | 4-23 |
| Air bleed | 140 |
Extra info #
- Mixing screw internal sleeve and internal o-ring
- Throttle shaft double plastic seals
- It only says Weber on top cover Made in Poland.
- Sometimes also no ‘Made in …’ on top cover
- Many sold afterwards in aftermarket as spares
Pictures #
Remarks #
- The later spare aftermarker carburettors no longer had a fuel filter and cover
- Made in Italy is also no longer on them
28IMB10-250 #
| Used on | Fiat 126 650cc from 1985 (126A1 076) (FOS Weber) |
| Main | 115 |
| Stationair | 0.45 |
| Emulsion | F8 |
| Air correct | 195 |
| Starter | F5/90 |
| Needle | 1.25 |
| Venturi | 4-23 |
Extra info #
- Mixing screw internal sleeve and internal o-ring
- Throttle shaft double plastic seals
- Manufacturer FOS (no Weber logo)
- On lid Licencja Weber Made in Poland
Pictures #
28IMB12-250 #
| Used on | Fiat 126 Nuova 652cc from 05-1985 (FOS Weber) |
| Main | 115 |
| Stationair | 0.50 |
| Emulsion | F8 |
| Air correct | 195 |
| Starter | F5/90 |
| Needle | 1.25 |
| Venturi | 4.5-23 |
| Air bleed | 140 |
Extra info #
- Mixing screw internal sleeve and internal o-ring
- Throttle shaft double plastic seals
Pictures #
The source of this information is unknown. The owner of the pictures is unknown as well. Are you the owner of the pictures, please contact us if you want.
