21XZ-R VII Engine

21XZ-R VII Engine

The 21XZ-R advantage: more time from every tank!

In the pits, time is the enemy and O.S. 21XZ-R can defeat it. They can run a full 10-minute heat on just one tank of fuel, while most other engines require two. That puts you a pit stop ahead of the pack and in sole possession of the lead to the checkered flag. The 21XZ-R VII's aggressive timing puts explosive acceleration and top-end speed at your fingertips, while surprising starting ease lets you unleash its race-winning potential right out of the box.

Construction Features

21M carb
The 21M carb is unmatched for smooth, linear acceleration. Performance-tuning options include a carb restrictor as well as four adjustable settings.
  • Specifications
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Stock Number: OSMG2042
Displacement: 0.212 cu in (3.49 cc)
Bore: 0.640 in (16.27 mm)
Stroke: 0.661 (16.8 mm)
Practical rpm: 4,000-45,000
Output: 2.71 hp @ 33,000
Weight: 12.1 oz (343 g)
Includes: RP7 Turbo glow plug, exhaust seal ring, 0.01 & 0.02 mm cylinder head gaskets, 8.5 mm (purple) carb restrictor, flywheel collet & exhaust, carb and fuel nipple dust caps.

Primary Accessories

Stock Number Mfr Number Product Description Quantity Needed
 ODOP3320   ODOP3320  O'Donnell 20% Racing Quart 1

Field Equipment

Stock Number Mfr Number Product Description Quantity Needed
 DTXP0310   DTXP0310  Duratrax Ultimate Glo-Starter C 1
 HCAP2550   HCAP2550  Hobbico 4-Way Wrench w/Plug Storage 1
 OSMG2384   72412000  O.S. Super Air Cleaner 202 1

Optional Accessories

Stock Number Mfr Number Product Description Quantity Needed
 DTXP0315   DTXP0315  Duratrax Ultimate Glo-Starter D 1
 DTXP0320   DTXP0320  Duratrax Ultra Slim AA Glow Starter 1
 DTXP3000   DTXP3000  Duratrax Rapid Heat Glo-Starter w/Charger 1
 DTXP5701   DTXP5701  Duratrax 1/10 & 1/8 Universal Starter Box 1
 DTXR0185   DTXR0185  Duratrax Engine Tuning Screwdriver 1
 DTXR0187   DTXR0187  Duratrax Engine Tuning Tool 1
 HCAP3001   HCAP3001  Hobbico After Run Engine Oil 2 Fl Oz 1
 OSMG2389   72412200  O.S. 202 Elements (4) 1
 OSMR2976   71521000  O.S. Long Socket Wrench With Plug Grip 1