Depends on the temperature where you live, my bike's been running fine over here in sunny old England using 10W 30/40
20W-50
80W 90 if using conventional. If using synthetic, 20W 50 will work. Also harley has Formula +.
For a 1997 Harley-Davidson Road King, the recommended transmission oil is a high-quality 20W-50 motor oil, specifically formulated for use in Harley motorcycles. You can also use Harley-Davidson's own products, such as their Transmission Lubricant or their Synthetic 20W-50 oil. Always check the owner's manual for specific recommendations and specifications to ensure optimal performance.
No brainier here 20W-50 An yes I ride a 1990 FXR so I do know
A motorcycle grade 20w 50. Harley 360 or Harley Screamin' Eagle Syn3 Mobile 1 20w50 for V twins. Oil must be rated for use in 4 cycle air cooled engines.
Only the weight of the oil, 20w 40 is thiker than the 15w40, 20w 40 is the best oil for the old cars although 15w40 is very easier cold start ...
The amount will depend on the Model, the oil weight is 20W-50. I recommend Amsoils 20W-50 Synthetic Motorcycle Oil (MCV) that's all I run in the 1990 FXR Hope This Helps.
4 qts w/ filter 20W 50 air cooled oil, pref harley brand
The W stands for Winter. The oil is 20 weight when cold so it will flow easier, and becomes 50 weight when it is at full operating temperature.
20w-50 same as engine oil; my new answer I've always used 80-90 but it gets hot here in the desert
20W-50 motoroil is the correct weight for many air cooled engines. This weight of oil is thicker and tolerates higher engine temperatures. Harley Davidson motorcycles, turbocharged automobiles are two common uses. One additional consideration would be the use of synthetic motoroils as these oils do not suffer breakdown (boiling off, burning, blackening) at higher engine temperatures. Examples: Mobil One Synthetic 20W-50.
20W-50 motoroil is the correct weight for many air cooled engines. This weight of oil is thicker and tolerates higher engine temperatures. Harley Davidson motorcycles, turbocharged automobiles are two common uses. One additional consideration would be the use of synthetic motoroils as these oils do not suffer breakdown (boiling off, burning, blackening) at higher engine temperatures. Examples: Mobil One Synthetic 20W-50.