| lubrication | |
|---|---|
| engine bearing surfaces lubricated from a petrol/oil mixture in a 25:1 (4 per cent) ratio. Gearbox and primary drive shafts run in oil bath which also feeds main bearings. | |
engine |
|
| bore | 55 mm |
| stroke | 52 mm |
| cacity | 123 cm |
| number of cylinders | 1 |
| compression ratio | 10 ± 5:1 |
| maximum power output | 12 bhp at 7000 rpm |
| maximum torque output | 9.1 lb. ft. at 6700 rpm |
| ignition timing (fixed) | 2.5-2.9 mm btdc |
| cb gap setting | .40-.48 mm |
| sparkplug | Champion N3 |
| thread size | 14 mm X 3/4 in. reach |
| porting | piston controlled |
| fitted ring gap | .008-.012 in. |
| NB—bore is chromed and the piston must be matched to a particular barrel. Letters are stamped on the top fin of the barrel and on the piston crown to facilitate matching. | |
|
crankshaft |
|
the crank and flywheels are pressed together and are only available as an assembly, complete with conrod. |
|
| big-end | roller bearing |
| driveside main | ball bearing |
| timing side main | roller bearing |
| crankshaft endfloat | zero |
| (the shaft is pulled up to the driveside main bearing) | |
|
fuel system |
|
| carburettor | Bing 2/26/64 |
| nominal bore | 24 mm |
| main jet needle jet 1208 | 120 |
| needle position | 3rd notch from top |
| pilot jet | 30 |
| idling air screw | 1.5 turns open |
The Puch M125 was sold in Canada and the USA under the Allstate brand. Similar to Vespa and Gileral products.
Produced in Austria, the M125 was reknowned for its robust motor and general reliability. After producing a line of split-singles since the 1920s, the M125 was the first “conventional” two-stroke produced by Steyer-Puch and was quickly adopted for trials work, especially ISDT-type competition. Interestingly, the cylinder is chrome plated.
For racing the displacement was increased to 175cc and six-speed gearbox was used.
