Royal Enfield 148671/B – Cap, Engine Mount Boss (Frame Plug) for Interceptor 650 & Continental GT 650 (BS4 Twins)

Royal Enfield part 148671/B is the genuine “CAP, ENGINE MOUNT BOSS” used on the 650 Twin frame to plug and protect the engine-mount bosses on the chassis. Official parts portals list 148671/B as a certified OEM spare, described either as “CAP, ENGINE MOUNT BOSS” or “BOUCHON CADRE / frame plug”, confirming that it’s the small cap which presses into the frame around the engine mounting points.

SOLD AS A SET OF 2 PCS 

Royal Enfield microfiche for the Continental GT 650 Euro 4 (BS4) and Interceptor 650 Twin Euro 4 shows 148671/B in the frame / chassis diagram with quantity “2”, sitting near the engine cradle and mount brackets. A factory “Fast Moving Parts for Retailers” sheet explicitly lists “148671/B – CAP, ENGINE MOUNT BOSS – CONT GT 650 BSIV”, and the 2022 RE retailer handbook categorises it under TWINS as a non-current model (i.e., BS4 650 Twins, pre-BS6 update).

Functionally, this cap seals the open engine-mount bosses on the frame, improving corrosion protection, cleanliness and finished look. Over time, these small plugs can fall out during engine work, frame swaps or accident repairs, leaving ugly open holes that collect water and dirt. Replacing them with genuine 148671/B restores the factory look of your Interceptor 650 or Continental GT 650 BS4 and keeps the chassis looking neat..

Key Features

• Genuine Royal Enfield OEM part – 148671/B, CAP, ENGINE MOUNT BOSS, also labelled as frame plug (bouchon cadre) on EU microfiche.

• Specifically assigned to the frame assembly of Continental GT 650 Euro 4 & Interceptor 650 Twin Euro 4.

• Listed by Royal Enfield internal documents as “Cap, Engine Mount Boss – CONT GT 650 BSIV – TWINS”, confirming its use on 650 BS4 Twins.

• Press-fit cap that closes exposed engine-mount bosses on the frame cradle, helping keep water, mud and road grime out.

• Restores a clean, finished OEM look when original caps are missing after engine removal, crash repair or repaint.

• Correct dimensions & material from factory drawings – no loose fit or rattling like universal frame plugs.
  

• Backed by multiple official and dealer sources (Bike-Parts-RoyalEnfield, Azmotors, EU RE portals, FortNine, OEMShip) to minimise fitment guesswork.

Compatibility Table 

Platform rule:

• ✅ Confirmed: 650 Twins – BS4 / Euro 4/ BS6 GT 650 AND INTERCEPTOR 650
  

• Interceptor 650 & Continental GT 650 BS6 / E5 
  

Variants

Microfiche shows “Normal Qty Required: 2” per 650 Twin frame.

Set of 2 PCS 

FREQUENTLY BOUGHT TOGETHER 

PAIR WITH 148670/B – Cap, Swingarm Boss  

FAQs

Q1. What does Royal Enfield 148671/B actually do?
It is a small press-fit cap that plugs the engine mounting bosses on the frame of the 650 Twins. It keeps dust, water and mud out of those cavities and gives the engine cradle area a neat, finished OEM look instead of open holes.

Q2. Which bikes are 100% confirmed for 148671/B?
Official microfiche and RE retailer docs confirm fitment for Continental GT 650 Euro 4 (BS4) and Interceptor 650 Twin Euro 4 (BS4). The RE fast-moving parts sheet calls it out as “Cap, Engine Mount Boss – CONT GT 650 BSIV – TWINS”, which covers BS4 650 Twins sold in India and export markets.

Q3. Will this fit the newer BS6 / E5 Interceptor & GT 650 or Super Meteor 650?
There is no explicit BS6/E5 microfiche evidence yet linking 148671/B to later 650 platforms. The safe approach is:

• If your parts book specifically lists 148671/B, it should fit.

• If it doesn’t, or if you own a Super Meteor 650 / Shotgun 650 / Bear 650, assume it is not compatible unless confirmed by a Royal Enfield dealer with your VIN.

Q4. How many engine mount boss caps does my 650 Twin need?
The Continental GT 650 Twin frame diagram shows normal quantity 2 for 148671/B – typically one cap per boss around the lower engine mount area. If both caps are missing or aged, it’s best to buy the pair and replace together.

Q5. Is this cap structural or just cosmetic?
It is not a structural part – it doesn’t carry load like the engine-mount bolt or bracket. It is a protective/finishing plug that prevents contamination and improves appearance. However, keeping the bosses clean does help make engine removal/installation easier in the long run.