Blue Line 1100-4037 right crankcase cover for CSC and 139QMB scooters, outer face with reinforcing ribs and oil-filler opening Blue Line 1100-4037 right crankcase cover for CSC and 139QMB scooters, outer face with reinforcing ribs and oil-filler opening
Blue Line 1100-4037 right crankcase cover for CSC and 139QMB scooters, inner face with oil passages and mounting holes Blue Line 1100-4037 right crankcase cover for CSC and 139QMB scooters, inner face with oil passages and mounting holes
Blue Line 1100-4037 CSC and 139QMB right crankcase cover, central opening measured at 33 mm Blue Line 1100-4037 CSC and 139QMB right crankcase cover, central opening measured at 33 mm
Blue Line 1100-4037 CSC and 139QMB right crankcase cover, lower threaded oil screen opening measured across at approximately 28 mm Blue Line 1100-4037 CSC and 139QMB right crankcase cover, lower threaded oil screen opening measured across at approximately 28 mm
Blue Line 1100-4037 right crankcase cover for CSC and 139QMB scooters, outer face with reinforcing ribs and oil-filler opening
Blue Line 1100-4037 right crankcase cover for CSC and 139QMB scooters, inner face with oil passages and mounting holes
Blue Line 1100-4037 CSC and 139QMB right crankcase cover, central opening measured at 33 mm
Blue Line 1100-4037 CSC and 139QMB right crankcase cover, lower threaded oil screen opening measured across at approximately 28 mm

Blue Line

Blue Line 139QMB Right Crankcase Engine Cover - 50cc

SKU 1100-4037
$22.00
Shipping calculated at checkout.
Description

Get your engine repair moving with this Blue Line right-side crankcase cover for Chicago Scooter Company go., go. MAX, Pug50, Bella Classic 50 and Nitro Sport 50 scooters. Built for the matching 139QMB four-stroke engine configuration with a 47-tooth oil-pump gear, it replaces a damaged cover so you can get back to enjoying your scooter.

Key Features

  • Right-side replacement: Restores the crankcase cover on compatible CSC and 139QMB scooter engines
  • 47-tooth pump-gear configuration: Match this requirement to your engine before ordering
  • Detailed casting: Includes mounting holes, internal ribs and threaded oil-service openings
  • Repair-ready fit check: Compare the mounting pattern, passages and openings with your existing cover

Technical Specifications

  • Brand: Blue Line
  • Part number: 1100-4037
  • Part type: Crankcase cover
  • Position: Right side
  • Engine platform: 139QMB / QMB139 four-stroke
  • Pump gear requirement: 47 teeth
  • Central opening measurement: Approximately 33.04 mm
  • Lower threaded opening measurement: Approximately 27.93 mm across the opening; not a thread-size specification
  • Quantity: One cover

Compatibility

Chicago Scooter Company model Required configuration
go. / go. Max Matching 139QMB 50cc four-stroke engine with 47-tooth oil-pump gear
Pug 50, Bella Classic 50, Nitro Sport 50 Matching 139QMB 50cc four-stroke engine with 47-tooth oil-pump gear

 

Universal Fit 139QMB Engine Applications

Compatible 139QMB-based 50cc and 80cc-converted setups must retain the matching cover configuration and 47-tooth pump gear.

Engine codes Fitment requirement
139QMA, 139QMB, 1P39QMB, 1P39QMA-2, YN139QMB, JJ1P39QMB, 139FMA-2, BD1P39QMB, BN139QMB, 147QMD; other QMA and QMB models Match the cover mounting pattern, oil passages, openings, and 47-tooth pump-gear configuration

 

Engine-code letters alone do not establish fitment. Compare your existing cover and oil-pump gear before ordering. Opening measurements are comparison references, not confirmed thread dimensions.
Product Diagrams
Features
  • Right-side crankcase replacement cover
  • For matching 139QMB four-stroke engines
  • Requires 47-tooth oil-pump gear configuration
  • Fits CSC go., go. MAX, Pug50, Bella Classic 50 and Nitro Sport 50
  • Mounting pattern and oil passages must match the original cover
Specifications

Brand: Blue Line; Part number: 1100-4037; Type: Crankcase cover; Position: Right; Engine platform: 139QMB / QMB139 four-stroke; Pump gear requirement: 47 teeth; Central opening comparison measurement: Approximately 33.04 mm; Lower threaded opening comparison measurement: Approximately 27.93 mm, not a thread specification; Quantity: One cover
Model Fitments

CSC go., go. MAX, Pug50, Bella Classic 50 and Nitro Sport 50 with matching 139QMB 50cc four-stroke engine and 47-tooth oil-pump gear; Matching 139QMB-based 80cc conversions; Engine codes: 139QMA, 139QMB, 1P39QMB, 1P39QMA-2, YN139QMB, JJ1P39QMB, 139FMA-2, BD1P39QMB, BN139QMB, 147QMD and other QMA/QMB models subject to matching mounting pattern, oil passages, openings and pump gear; Existing make/model applications require this configuration
  • Same day shipping for orders placed before 2PM (CST) M-F
  • 30-day return period on eligible items
  • Flat-rate shipping for orders shipped to the 48 Contiguous United States.
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