20w50 is recommended in temperate zones.
If you live in an area where the temperature does not dip below 75 degrees Fahrenheit, you can use regular 50.
Clarification: If you live in an area that has cold winters, use 20w50
The "w" in ALL OILS does not refer to weight. It refers to winter. The "20w" would indicate there are additives in the oil that make it behave like 20 weight oil in cold weather.
Straight weighted oils can be used if you live in a climate that stays above the oils winter rating. All of this information is listed on a chart in your Harley Davidson user manual. If you do not have one, you should pick one up!
Use 30w synthetic or 10w30 synthetic. 30w is preferred.
no
It can vary between 30W and 10W30. L-heads use 30W, OHVs often use 10W30.
Sea 30w
Hd 30w
I like Mag 1 HD 30W oil but it's hard to find, Castrol's HD 30W would be my second choice. All major brands of oil today are of excellent quality. You can use any of them and know that your engine will be protected. I personally use Pennzoil.
30W for summer
SAE 30W
straight 30W, 10-30w and 10-40w are all ok and recommended
I would not recommend it, stick with the straight 30W.
30w, 10-30w or 10-40w
30w and if you want i higher quality oil, use synthetic