Originally Posted by MazdaRangerGuy
Please don't run 10w30 in this engine.. it will sludge it up quick and in a hurry, even if it is synthetic.
Use 5w30 at the HEAVIEST, 5w20 if the temperature will go below 0F
Well, that is a new one. I thought I heard them all, coming from an air-cooled V-twin discussion board. You think car guys have oil opinions, I've seen fights over oil types.
Oil will NOT "sludge-up" by itself.
I'm guessing thaty straight 50 weight could be used in these engines without major damage, but it would not sludge up. Sludge comes from contamination, not type of oil.