How to Change the Coolant in a 1986 Yamaha PW80: Essential Owner Guide
Shop parts for a 1986 Yamaha PW80 Dirt Bike.
If you own a 1986 Yamaha PW80, you know how crucial regular maintenance is to keep your classic mini-moto running strong. While the PW80 is often cited as "air-cooled," some special versions and upgrades introduce a simple coolant system or riders may want guidance for similar youth-class models. Here–s a step-by-step proprietary guide just for MotoSport riders covering everything you need to know about changing the coolant on your PW80 or similarly-configured cooling system dirt bike.
Why Coolant Change Matters
Fresh coolant protects your Yamaha–s engine by preventing overheating, corrosion, and scale buildup. Proper maintenance also helps extend gasket and seal life, which is vital for maintaining reliability in older models like the 1986 PW80.
Tools & Supplies You'll Need
- Recommended motorcycle coolant (pre-mixed or concentrate plus distilled water; never tap water)
- Socket set and screwdrivers
- Drain pan
- Funnel
- Clean rags
- Crush washer (if replacing the drain bolt washer, recommended)
- Safety gloves & goggles
Step-by-Step Coolant Change Process for 1986 Yamaha PW80
- Let the Bike Cool
Make sure the engine is completely cool before beginning to avoid burns. - Locate the Drain Bolt
Find the coolant drain bolt–typically at the lowest point of the cooling system, often near or on the water pump cover. Place a drain pan underneath. - Remove the Radiator Cap (if equipped)
Opening the cap before draining helps coolant flow out faster and ensures a complete drain. - Drain Old Coolant
Carefully remove the drain bolt and let all old coolant flow into the pan. For bikes with a reservoir, drain and rinse it with a bit of distilled water before refilling. - Inspect and Clean
Inspect the drain bolt washer. Replace with a new crush washer if worn. You can gently flush the system with distilled water if buildup is present, then drain again. - Reinstall the Drain Bolt
Fasten the bolt snugly, but do not overtighten. Check your manual for torque specs. - Add New Coolant
Slowly pour recommended coolant into the radiator (or fill point) using a funnel. Pour in stages to let air escape. If your system has a bleeder screw, crack it open until coolant flows out, then close. - "Burp" the System
Gently squeeze the radiator hoses to expel trapped air bubbles. Tip the bike side to side if needed to allow air to rise out of the system. - Check Level & Start Engine
Top off the coolant to the base of the filler neck. Start the engine and let it idle until it reaches normal operating temperature–with the cap off. Watch for bubbles and add coolant if the level drops. - Final Top-Off and Inspection
Once you've run the engine and ensured all bubbles have escaped, turn off the bike and let it cool to ambient temperature. Top off the radiator as needed and fill the reservoir (if equipped) to its cold line. Replace any shrouds or covers. - Dispose of Old Coolant Properly
Pour used coolant into a sealed container and take it to a recycling center or auto parts store. Never dump coolant outdoors or down the drain.
PW80 Owner–s Notes: Model-Specific Tips
- The original 1986 Yamaha PW80 is famously air-cooled from the factory. If yours has an aftermarket or customized liquid cooling system, always follow the setup–s specific fill and bleed instructions.
- Always use coolants designed for motorcycles. Many automotive coolants can harm seals or cause internal corrosion. Look for silicate-free formulas.
- Inspect cooling hoses for cracks or softness. Aging rubber is common on bikes of this era–replace if needed for safety and reliability.
- If you experience recurring coolant loss without visible leaks, check for possible head gasket or water pump seal issues, especially on older bikes.
MotoSport Insider Pro Tips
- Never run the bike without coolant, even briefly. Severe engine damage can result in seconds.
- Keep a maintenance log for all services, including coolant changes, part numbers, and dates for future reference.
- Always let the bike cool to ambient before opening any part of the cooling system to avoid burns or injury from hot pressurized fluids.
Keep your 1986 Yamaha PW80 running cool and reliable with routine coolant changes and regular inspections. For all replacement parts, upgrades, and maintenance supplies, MotoSport has you covered for every ride.
Related Shopping Categories
Shop Radiators for a 1986 Yamaha PW80 Dirt Bike.
Shop Coolant for a 1986 Yamaha PW80 Dirt Bike.
Shop Temperature Sensors for a 1986 Yamaha PW80 Dirt Bike.
Shop Tools for a 1986 Yamaha PW80 Dirt Bike.
Shop Radiator Hoses for a 1986 Yamaha PW80 Dirt Bike.
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.