Specs and torque
- RS125 only, 1993 to 2006.
- Type 122 and Type 123 are separate.
- Double-check every figure on your own bike.
RS125 · 1993–2006
Specs and torque
Measured figures and fastener torque for the RS125 two-stroke, 1993 to 2006. The source is the workshop manual. The sentences are this site's.
Every number below is taken from Haynes manual 4298 (Aprilia RS50 and RS125 1993-2006). Where a later photograph of the same page corrected an earlier reading, the corrected figure is the one printed. Reed-valve data is not in the manual, so that line stays Not published.
Where the manual and this site disagree
Neither figure is dropped. The manual value is what you use when you are working to that book. The older record on this site stays visible beside it.
| Item | Haynes 4298 | Already on this site |
|---|---|---|
| Starter motor mounting bolts | 10 Nm in the engine torque table (chapter 2B), and 12 Nm in the electrical chapter (chapter 9). | Both figures are printed. This site does not average them to 11 Nm. |
| Carburettor | The carb table lists a Dell'Orto PHBH28BD for the 11 kW restricted RS125 and again for the 20 kW unrestricted RS125. It does not give a jet stack for a 34 mm carburettor. | The research brief records a Dell'Orto VHSB 34 on the Rotax 123 and a PHBH 28 on the Rotax 122. Both stay. A 34 mm carb on a Type 122 that left with the 28 mm carb is a modification, not a third stock specification. Do not put the PHBH jets in a 34 mm body. |
| Unrestricted power label | The unrestricted carb column is labelled 20 kW. | The research brief's open-bike homologation figures are about 21–23 kW and differ by generation. 20 kW is the manual's column label, not a replacement for those figures. |
| Spark plug | NGK BR10EG, electrode gap 0.5–0.7 mm. | A derestriction blog in the research brief says to change from a BR8EG to a colder BR10EG. The manual extract does not list a BR8EG. |
Notes from readers
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Sources
Research brief dated 24 October 2026. Where this page says “the brief”, that is the sourced master plan behind the first edition.