21XZ-M Inboard Marine Engine
A proven on-road powerhouse comes to the boating world!
Based on the 21XZ-R - Performance at the 2011 IFMAR 1/8 scale On-Road World Championships — the 21XZ-M Inboard Marine Engine takes that race-winning technology and applies it to dominating .21-size boat competition! Many of the performance features found on the 21XZ-R are here; and by utilizing a water-cooled cylinder head and big-bore carb, the 21XZ-M will assert itself on the water with the same resounding success!
- The cylinder head is water-cooled and blue anodized
- The 21D big-bore carb allows for the use of high-nitro fuel
- The crankshaft is silicone-filled for more efficient intake; two tungsten weights provide optimum balance for low- and mid-speed torque
- The cylinder liner has seven scavenger ports and three exhaust ports, for better, more efficient combustion
- The piston is balanced and lightened, and the con rod had been made more durable
- An RP7 turbo plug is included
21D big-bore carburetor
Water-cooled, blue anodized cylinder head
- Specifications
- Exploded Views
- Parts Listing
- Accessories
- Gallery
Stock Number: OSMG1621
Displacement: 0.21 cu in (3.5 cc)
Bore: 0.640 in (16.27 mm)
Stroke: 0.661 in (16.8 mm)
Practical rpm: 4,000-45,000
Output: 2.71 hp @ 33,000 rpm
Weight: 10.85 oz (307.5 g)
Includes: 21D carb, RP7 turbo plug, flywheel collet, 0.2 mm head gasket, dust caps
Requires: 10-30% nitro boat fuel (20% recommended for break-in), exhaust system, glow plug igniter
NOTE: Do not use car or truck fuels; use fuels designed for boat use
Recommended Product
AQUP2230 AquaCraft® Models 30% Boat Fuel (Quart)
AQUB6903 AquaCraft Models 3" Fuel Line (3/32" id, 3/16" od)
AQUP2250 AquaCraft® Models 50% Boat Fuel (Quart)
AQUB9720 GrimRacer™ 40 x 52 Tri-Metal Propeller
AQUB9715 GrimRacer 40 x 53 Tri-Metal Propeller
Recommended Options
Note: items marked with an asterisk (*) are included.
OSMG2704 RP7 Turbo Glow Plug Cold*
OSMG2703 RP6 Turbo Glow Plug Medium
OSMG2715 RP8 Turbo Glow Plug Cold
OSMG8876 Exhaust Coupler .21
OSMG5872 Super Can Filter Large
OSMG9401 Lock Washer 3mm
OSMR2977 O.S. Speed Plug Wrench
OSMR3000 O.S. Speed 10-Piece Tool Set
See your local hobby dealer for additional recommendations.
Displacement: 0.21 cu in (3.5 cc)
Bore: 0.640 in (16.27 mm)
Stroke: 0.661 in (16.8 mm)
Practical rpm: 4,000-45,000
Output: 2.71 hp @ 33,000 rpm
Weight: 10.85 oz (307.5 g)
Includes: 21D carb, RP7 turbo plug, flywheel collet, 0.2 mm head gasket, dust caps
Requires: 10-30% nitro boat fuel (20% recommended for break-in), exhaust system, glow plug igniter
NOTE: Do not use car or truck fuels; use fuels designed for boat use
Recommended Product
AQUP2230 AquaCraft® Models 30% Boat Fuel (Quart)
AQUB6903 AquaCraft Models 3" Fuel Line (3/32" id, 3/16" od)
AQUP2250 AquaCraft® Models 50% Boat Fuel (Quart)
AQUB9720 GrimRacer™ 40 x 52 Tri-Metal Propeller
AQUB9715 GrimRacer 40 x 53 Tri-Metal Propeller
Recommended Options
Note: items marked with an asterisk (*) are included.
OSMG2704 RP7 Turbo Glow Plug Cold*
OSMG2703 RP6 Turbo Glow Plug Medium
OSMG2715 RP8 Turbo Glow Plug Cold
OSMG8876 Exhaust Coupler .21
OSMG5872 Super Can Filter Large
OSMG9401 Lock Washer 3mm
OSMR2977 O.S. Speed Plug Wrench
OSMR3000 O.S. Speed 10-Piece Tool Set
See your local hobby dealer for additional recommendations.
Primary Accessories
| Stock Number | Mfr Number | Product Description | Quantity Needed |
| GPMQ4131 | GPMQ4131 | Great Planes Silicone Fuel Tubing Standard 3' | 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 |
| 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 |
| OSMG8876 | 72106300 | O.S. Exhaust Coupler 21 | 1 |
| PAAP1453 | PT31 | Pacer Zap After-Run Engine Oil 1 oz | 1 |
| SULP1826 | S626 | Sullivan Starter Belt Boats/Heli | 1 |
