J Bautz Aktiengesellschaft Saulgau AS 120
Built: 1951–1960 · Series: AS
More machines from model year 1951
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J Bautz Aktiengesellschaft Saulgau, AS line: the water-cooled two-cylinder diesel AS 120, 1,250 cc, 8.8 kW, with a recorded rated-speed increase from 1,750 to 1,820 rpm from 1954
J Bautz Aktiengesellschaft, based in Saulgau, Württemberg, built two-cylinder tractors alongside its single-cylinder models in the 1950s. Within the AS line, the AS 120 moved to two cylinders instead of one, and to genuine pump-driven water cooling in place of the simpler thermosiphon system used on the marque's earlier models.
Read on 3 more paragraphs
The two-cylinder engine of 1,250 cc produces 8.8 kW (12 hp). Worth noting is the rated-speed increase recorded during production: from 1,750 rpm up to 1,820 rpm from 1954 onward. At a weight of 830 kg, a wheelbase of 1,550 mm and a width of 1,475 mm, the AS 120 is, despite its second cylinder, lighter than the marque's older single-cylinder model.
A rated speed raised mid-production points to further development of the twin during its production run, whether to lift output or to suit changing implements. With a top speed of 19 km/h, the AS 120 remains clearly within the slow tractor category capped at 40 km/h.
Buying a used AS 120 calls for checking the water pump and radiator, as these early pump-driven cooling systems were more failure-prone than the plain thermosiphon design they replaced. The cylinder head gasket and valve clearances of the twin deserve particular attention on a machine this old. Parts for these early two-cylinder Bautz models are scarce and generally found only through tractor collectors.
Sources: SpecCodex-Register: Kennwerte des Modells AS 120
Technical data
Engine
| Fuel | dieselcorrect |
|---|---|
| Power | 12 hp (8.8 kW)correct |
| Rated speed | 1,750 rpmcorrect |
| Cylinders | 2correct |
| Displacement | 1,250 cm³correct |
| Cooling | water-cooledcorrect |
Dimensions and weights
| Length | 2,355 mmcorrect |
|---|---|
| Width | 1,475 mmcorrect |
| Height | 1,490 mmcorrect |
| Wheelbase | 1,550 mmcorrect |
| Ground clearance | 400 mmcorrect |
| Unladen weight | 830 kgcorrect |
Drivetrain and chassis
| Drive | rear-wheel drivecorrect |
|---|---|
| Gearbox | 4/1- oder 5/1-Getriebecorrect |
| Front tyres | 4.50-16correct |
| Rear tyres | 8-24correct |
| Top speed | 19 km/hcorrect |
Origin and approval
| Construction | frameless unit constructioncorrect |
|---|---|
| Units built | 11,682correct |
Where this model stands
Power-to-weight ratio: 10.6 kW/t (9 kW / 0.8 t)
Power class: Compact (< 40 hp)
Stronger than 2% of the tractors in the register — out of 15,663 models with a stated power figure.
Calculated from the documented figures above — not a rating.
Frequently asked questions
How much power does the J Bautz Aktiengesellschaft Saulgau AS 120 have?
The J Bautz Aktiengesellschaft Saulgau AS 120 delivers 12 hp.
How much does the J Bautz Aktiengesellschaft Saulgau AS 120 weigh?
The unladen weight is 830 kg.
What engine does the J Bautz Aktiengesellschaft Saulgau AS 120 have?
2 cylinders, 1,250 cm³ displacement, Diesel.
How fast does the J Bautz Aktiengesellschaft Saulgau AS 120 go?
Top speed is 19 km/h.
What are the dimensions of the J Bautz Aktiengesellschaft Saulgau AS 120?
2,355 mm × 1,475 mm × 1,490 mm.
When was the J Bautz Aktiengesellschaft Saulgau AS 120 built?
Production years: 1951–1960.
What to check before buying
- Check the hour meter against the service records — a replaced instrument is the most common gap.
- Compare the data plate and chassis number with the papers.
- Check the weights in the papers against the figures here — attachments change them.
- Check front and rear tyre sizes: mismatched pairs strain the drivetrain.
- Shift the gearbox cold and warm — jumps only show up at temperature.
- Load the hydraulics and watch for sag.
- Ask about parts availability for this build year — the running costs hang on it.
A general list for this type of machine — no substitute for an inspection or an appraiser.
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This page carries 20 individual figures for this model. They come from 1 recorded source; every figure can be traced there. What we cannot document is not here — we leave gaps open rather than estimate them.
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Sources: Wikibooks Traktorenlexikon (CC BY-SA 4.0) (retrieved August 2026) · Values adopted and presented in our own form; changes from the source are possible. · How we check the data
Tractor in 3D section
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