Flushed my coolant in my 2019 Kawasaki Vulcan S and swapped it with this, so far engine temps are noticeably lower and engine runs great.IF YOU FLUSH YOUR COOLANT, DO IT RIGHT. Get at least 1 gallon of distilled water. Drain your coolant system from the lowest point (usually water pump) then fill it completely with the distilled water and drain it again. Empty/flush the overflow reservoir until clear, refill the system, then run the engine for 20-30 seconds and flush the system again. If your capacity is 2 full quarts, you should be good to go after using the entire gallon of distilled water. Make sure you get on the bike and lean it left and right repeatedly while the drain plug is removed to drain out any clinging water.Fill your reservoir with coolant to the fill line, then SLOWLY start filling your radiator. Most bikes the radiator cap is the highest point in the loop while on the kickstand. I repeat, WHILE. ON. THE. KICKSTAND. Do not fill the system with the bike upright, you WILL trap air. Once full put the cap on and lean the bike left and right a bunch of times. Squeeze all radiator hoses slowly and repeatedly to free up any trapped air. Place back on kickstand, take cap off, and refill- you will have freed up some air. Repeat until the radiator is completely full when removing the cap. Tighten all bolts, fittings, etc.After you check and it's still completely full, now comes the hardest part. Patience. You need to run the bike for 5-10 minutes, maybe 15-20 depending on the temperature outside. You need to run the engine until the fan kicks on 2-3 times and let it run fully. After it's done that, shut it off and WAIT. Do not even think about touching that bike until the engine is COMPLETELY cool. Minimum 2-3 hours (again, depending on outside temps)Once the bike is COMPLETLEY cool, if you remove the radiator cap and there is still absolutely no space to add more coolant, you are all done. If there is space, add coolant. Check the coolant level after a few rides to be sure all the trapped air has been freed up. Again- ONLY WHEN COMPLETLEY COOL.