21XM VII Outboard Marine Engine
The next generation in .21 outboard marine performance!
Leave it to the engineers at O.S. to concoct a sure-fire recipe for marine racing success! First, they started with the 21XM, O.S.' exceptional outboard engine and winner of 11 championships in a 4-year span. They then upgraded the cylinder head and muffler. The result: the 21XM VII, an air-cooled powerhouse that's even faster than the original!
- The machined head is air-cooled, which insures optimum engine temperature under any conditions
- The muffler has been extended to generate more torque and power
- With perfectly matched port timing, exhaust outlets, compression ratio and carb bore, the 21XM VII is designed for competition, right out of the box
- The 20J carburetor has both high-speed and idle needles
- A pressure line from the muffler sends a steady flow of lubricants to the lower unit
- Prop height and angle can be adjusted independently
- Ball bearings minimize friction and wear for longer life and higher top-end speeds
- The bronze prop shaft assembly offers extreme durability
- A lightweight aluminum piston is performance-matched to a long-lasting ABN cylinder sleeve
- An exceptional value as well as a total competitive package, complete with a #8 glow plug and 42 x 1.2 carbon prop
Cooling the cylinder head with air is more reliable than water cooling, and prevents overcooling. It also adds the benefits of simpler construction and less maintenance.
While being larger than the muffler used with the .21XM, the VII's muffler is still just as easy to tune, still detachable for easier maintenance, and more responsive than a tuned pipe.
- Specifications
- Exploded Views
- Parts Listing
- Accessories
- Gallery
Stock Number: OSMG1720
Displacement: 0.211 cu in (3.46 cc)
Bore: 0.654 in (16.6 mm)
Stroke: 0.630 in (16.0 mm)
Practical rpm: 3,000-25,000
Output: 1.28 hp @ 25,000 rpm
Weight: 24.1 oz (682 g)
Prop Shaft Diameter: 3/16 in
Includes: mount, outdrive unit, E-2050-2 removable muffler, starter cone, #20J carb, #8 glow plug, steering bracket, throttle link assembly & 42 x 1.2 carbon prop
Requires: 10-50% nitro boat fuel with at least 18% oil content, starting equipment, fuel tubing
NOTE: Do not use car or truck fuels; use fuels designed for boat use
Displacement: 0.211 cu in (3.46 cc)
Bore: 0.654 in (16.6 mm)
Stroke: 0.630 in (16.0 mm)
Practical rpm: 3,000-25,000
Output: 1.28 hp @ 25,000 rpm
Weight: 24.1 oz (682 g)
Prop Shaft Diameter: 3/16 in
Includes: mount, outdrive unit, E-2050-2 removable muffler, starter cone, #20J carb, #8 glow plug, steering bracket, throttle link assembly & 42 x 1.2 carbon prop
Requires: 10-50% nitro boat fuel with at least 18% oil content, starting equipment, fuel tubing
NOTE: Do not use car or truck fuels; use fuels designed for boat use
Primary Accessories
| Stock Number | Mfr Number | Product Description | Quantity Needed |
| GPMQ4131 | GPMQ4131 | Great Planes Silicone Fuel Tubing Standard 3' | 1 |
| HCAP0200 | HCAP0200 | Hobbico 12 Volt Charger U/L Listed | 1 |
| HCAP0800 | HCAP0800 | Hobbico TorqMaster LC 12V 7Amp Battery | 1 |
| HCAP3200 | HCAP3200 | Hobbico TorqMaster 90 Deluxe 12V | 1 |
| SULP1826 | S626 | Sullivan Starter Belt Boats/Heli | 1 |
Field Equipment
| Stock Number | Mfr Number | Product Description | Quantity Needed |
| DTXP0310 | DTXP0310 | Duratrax Ultimate Glo-Starter C | 1 |
| OSMR2976 | 71521000 | O.S. Long Socket Wrench With Plug Grip | 1 |
Optional Accessories
| Stock Number | Mfr Number | Product Description | Quantity Needed |
| HCAP3001 | HCAP3001 | Hobbico After Run Engine Oil 2 Fl Oz | 1 |
| HCAP3205 | HCAP3205 | Hobbico Panel Ready TorqMaster 90 | 1 |
| ODOP3030 | ODOP3030 | O'Donnell 30% Boat Gallon | 1 |
| ODOP3130 | ODOP3130 | O'Donnell 30% Boat Fuel Quart | 1 |
| OSMG5872 | 72403050 | O.S. Super Can Filter Large | 1 |
