Royal Enfield 1570402 / 1570402/B – Piston Oil Ring for J-Series 350 – Classic 350 Reborn, Meteor 350, Hunter 350, Bullet 350 – Genuine OEM

The Royal Enfield 1570402 / 1570402/B – RING-PISTON (OIL) is the genuine 3rd / oil control ring for the new-gen J-Series 350 (349cc) engine used in the Classic 350 Reborn, Meteor 350, Hunter 350 and new Bullet 350. Official RE price lists describe 1570402/B as “RING-PISTON (OIL)”, and European parts portals list it as a genuine Royal Enfield oil ring.

The oil ring’s job is to scrape excess oil off the cylinder wall and return it to the crankcase while leaving just a thin film for lubrication. A worn or damaged oil ring leads to blue smoke, high oil consumption and fouled plugs. Replacing it with the correct OEM 1570402/B restores proper oil control and complements the 1st and 2nd compression rings (1570400/1570401) in a full top-end rebuild of your J-Series engine. 

Key Features 

• Genuine Royal Enfield OEM piston oil ring – Part No. 1570402 / 1570402/B – RING-PISTON (OIL).

• Designed as the 3rd / oil control ring for the 349cc J-Series 350 engine used on Classic Reborn, Meteor, Hunter and new Bullet 350. 

• Correct standard size ring as part of OEM ring set 1570400/01/02 for J-Series 350 (1st, 2nd and oil rings). 

• Maintains proper oil control, reducing smoke, plug fouling and excessive oil consumption compared to local aftermarket rings.

• Matches OEM material, tension and multi-piece design (where applicable) for reliable sealing and long life.

• Ideal when rebuilding a high-mileage J-Series 350 top-end or replacing a damaged or stuck oil ring.

• Manufactured to Royal Enfield tolerances, ensuring correct side clearance and ring groove fit.

• Supplied as one oil ring – perfect if only the oil ring is being replaced or if you’re assembling a top-end from separate OEM parts.

Compatibility Table 

Core spec: Oil control ring (3rd ring) for Royal Enfield J-Series 350 (349cc, air-oil cooled, EFI).

PLEASE CHECK PART NUMBER BEFORE PURCHASE 

Variants

• Single Variant (this listing):

  • Part Number: 1570402 / 1570402/B

  • Type: Piston Oil Ring 

  • Engine: J-Series 350 – 349cc

  • Size: Standard bore (no oversize suffix in OEM lists). 

(For a complete rebuild, pair with 1570400 – 1st ring and 1570401 – 2nd ring.)

FAQs

Q1. Is 1570402 the full ring set or only the oil ring?
It is only the oil control ring . The full J-Series ring set is usually listed as 1570400/01/02, which includes the 1st, 2nd and oil rings together. 

Q2. Will this oil ring fit my Classic 350 Reborn / Meteor / Hunter / new Bullet 350?
Yes – multiple genuine-parts sellers and kits clearly list 1570402 for All New Classic 350, Meteor 350, Hunter 350 and Bullet 350 (J-Series). 

Q3. Can I install 1570402 in an older UCE Classic 350 or Bullet 350?
No. Older UCE and cast-iron engines use different piston and ring part numbers. 1570402/B is specific to the J-Series 349cc platform and should not be used on UCE / CI motors without explicit confirmation from the RE microfiche.

Q4. Is this ring standard size or oversize?
OEM price lists and parts portals only list 1570402/B – RING-PISTON (OIL) with no oversize code, and it appears in the standard piston ring kit for J-Series 350. Treat this listing as standard bore. 

Q5. Should I change all rings or only the oil ring?
Best practice during an overhaul is to replace the full set (1st, 2nd and oil rings) and check piston/cylinder clearance and ring end-gaps to spec. Replacing only the oil ring is acceptable in very specific repair scenarios and should be decided by an experienced mechanic.