How to Change the Coolant in a 2022 GAS GAS MC 85
Maintaining the cooling system is vital for reliable performance and engine longevity in your 2022 GAS GAS MC 85. Regular coolant changes keep temperatures regulated during aggressive riding and prevent internal corrosion — essential for a high-revving 2-stroke like the MC 85. This step-by-step guide will walk you through a coolant change specifically for your model, with extra tips unique to this championship-proven mini motocross machine.
What You'll Need
- Fresh, high-quality motorcycle coolant (avoid automotive or straight water)
- Drain pan
- Socket set or spanners
- Shop towels/rags
- Funnel
- Flat-blade screwdriver (for radiator cap and plastics, if needed)
- Gloves and eye protection
Preparation: Safety First
- Make sure the MC 85 is completely cool. The coolant system can become pressurized and dangerously hot. Never open the radiator cap on a warm or running engine.
- Wash off any heavy dirt or mud from the radiator area to prevent debris from entering the cooling system during service.
- Stand the bike securely on a stand or level surface.
Draining the Old Coolant
- Remove the radiator cap by turning it counterclockwise. Do this slowly to avoid any residual pressure release.
- Position a drain pan under the lower water pump housing on the right side of the engine.
- Locate the coolant drain bolt. On the MC 85, this is typically on the water pump cover at the lowest point.
- Remove the drain bolt using the correct size socket and allow the coolant to flow out completely.
- Cycle the bike side to side gently (with the drain bolt out) to help evacuate trapped coolant.
Flushing the System (Optional, but Recommended)
- If the old coolant appears very dirty, flush the system with distilled water. Reinstall the drain bolt, fill with distilled water, run the engine briefly, then drain again.
Refilling with New Coolant
- Reinstall the drain bolt. Make sure to torque it to the manufacturer specification — overtightening can damage the pump housing.
- Slowly pour fresh coolant into the radiator until the level just reaches the bottom of the filler neck.
- The MC 85 features a bleeder screw on top of the cylinder head. Crack this bleeder to allow trapped air to escape as you fill. Tighten the bleeder once steady coolant flows out.
- Fill and bleed in stages, topping off after each time air is released from the bleeder.
- Reinstall the radiator cap firmly.
Final Steps – Bleed, Check, Clean Up
- Wipe up any spilled coolant — the ethylene glycol used in most coolants can be slippery and harmful to pets and the environment.
- With the radiator cap on, start the bike and let it idle for several minutes. Watch for leaks.
- Once cooled, check the coolant level again and top off if needed — air pockets sometimes work themselves out after a heat cycle.
- Recheck the drain bolt and bleeder for leaks following the first short ride.
Special MC 85 Tips
- The MC 85 shares core cooling system architecture with KTM and Husqvarna mini motocross models, but it's crucial to use only recommended coolants to avoid internal corrosion or water pump seal issues that can arise with improper fluids.
- Routinely check for mud build-up in the radiators after wet or muddy rides, as clogging is common and can drastically reduce cooling efficiency for this high-performance engine.
- If you race or ride in extremely hot environments, consider a performance coolant (compatible with aluminum radiators and magnesium engine cases) to maximize heat dissipation and engine protection.
- Monitor radiator fins for damage and keep the cooling system free of debris to prevent overheating, which is especially important for youth racers who may run the MC 85 at full throttle for long periods.
Maintenance Reminder
- Follow your maintenance schedule: Inspect coolant every 20 engine hours or every race weekend, whichever comes first. Change the coolant at least once per season, or more often in challenging conditions.
Keeping up with coolant changes will help your 2022 GAS GAS MC 85 perform at its best, lap after lap – whether on the starting gate or in the woods.
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Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your motorcycle's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.