This is the new 2025-edition Minicars Marine Special Edition O.S.SPEED R21-M06 3.5cc long-stroke competition engine. The R21-M06 has a new piston & liner, a new conrod, a new crankshaft & a ceramic main ball bearing.
Features:
- New DLC coated & balanced R21 Euro-II crankshaft with more timing
- New 9-port cylinder liner with 3-port exhaust
- New piston with 3 oil-grooves
- New Ceramic main ball bearing
- New Reinforced “R” conrod
- New RP6 Turbo plug (instead of RP7)
- O.S.Speed developed black crankcase with Minicars Marine Laser Engraving
- Black anodized water cooling head with Minicars Marine Special Edition Laser Engraving
- Backplate with steel thrust plate for lower friction and increased durability
- No carb included – choose your own carburetor (15mm diameter neck)
Suitable for competition boats (experience level ”high”):
- Hydroplanes
- Offshore (with gear deduction)
- Endurance (with gear reduction)
Recommended fuel:
- Hydroplanes: 12% nitro fuel with 8% Klotz Original Techniplate + 8% Klotz Benol oil
- Offshore: 12% nitro fuel with 8% Klotz Original Techniplate + 8% Klotz Benol oil
- Endurance: 12% nitro fuel with 8% Klotz Original Techniplate + 8% Klotz Benol oil
- We don’t recommend running the engine with less oil than the above recommended levels. You may add more recin/castor oil (Klotz Benol) in extreme conditions and heavy loads.
Optional parts:
- O.S. Remote R/C Needle (#OS71703009)
- M-Drive Remote R/C Needle Base Left (Black) (#MDM-NBL)
- M-Drive Remote R/C Needle Base Right (Gold) (#MDM-NBR)
- M-Drive Main NeedleDelete Adapter for all O.S. 3.5cc car slide carbs (#MDM-DDCF)
- O.S. Fuel Inlet Nipple Set (#OS22082950)
- M-Drive Short Marine Direct Drive Flywheel (w/o cone) (#MDM-DDFW)