Overview
We are proudly announcing O.S. SPEED R21GT for a relatively new category 1/8 GT class. The new engine aims at IFMAR world championship to be held in the United States in January, 2020. So the design of the engine is fully conformed to IFMAR regulation. The crankcase is modified version of R2101, cylinder/piston is new design: 5 scavenging ports + 3 exhaust port, the crankshaft is also newly designed: double counter weight made of Phosphor bronze for better torque, of course the crankshaft is DLC coated to minimize mechanical friction and with silicon filler for light weight. The carburetor is also new design, 22E(B)GT double adjustment type carburetor for smooth and better response from cornering with a 7.0mm restrictor, which conform to IFMAR regulation. The cooling head is designed to optimize heat dissipation and light weight.
- Bore
- 0.633" (16.08mm)
- Crankshaft Threads
- UNF 1/4-28
- Crankshaft Type
- SG
- Cylinder Type
- Five Scavenging Ports, three Exhaust Ports
- Cylinders
- Single
- Displacement
- 0.213 cu in (3.49cc)
- Engine (Only) Weight
- 13.2oz (369g)
- Muffler Type
- Tuned Muffler
- Oil Type & Content
- 12-16% Synthetic Oil Mixture in Fuel
- Plug Type
- RP6 Turbo Type, Medium Heat Range
- Power Type
- Glow
- Product Height
- Bottom/Mounting Tabs to top of Cylinder Head 3.4" (86.5mm)
- Product Length
- Backplate to Front Bearing, 2.5" (64.6mm)
- Product Width
- At Mounting Tabs 1.8" (45mm),
- RPM Range
- 4,000 - 42,000
- Stroke
- 0.677" (17.20mm)