Follow-up on my question from a while back -- 20w-50 mixed with straight 60 is holding up real well so far and the bike is much easier to kick start in colder weather. I'm sticking with it. Once we get up into the triple digit temps I'll see how it handles the heat and check back in. But at 90 mph at 60F it sounded fine and was still pulling hard.
For those interested, this particular engine does not like 20w-50, the motor sounds terrible on it in hot weather and for some reason it shears down really fast. This is a stock displacement 74 that will break the back tire loose on dry pavement in first gear without touching the clutch, running compression check says 215 in one cylinder and 235 in the other. I can see how it might be a little hard on oil -- and everything else.
For comparison, a stock everything 74 with an original factory cam and 8:1 pistons is doing fine on Mobil1 20w-50.
Thanks to all who helped.
For those interested, this particular engine does not like 20w-50, the motor sounds terrible on it in hot weather and for some reason it shears down really fast. This is a stock displacement 74 that will break the back tire loose on dry pavement in first gear without touching the clutch, running compression check says 215 in one cylinder and 235 in the other. I can see how it might be a little hard on oil -- and everything else.
For comparison, a stock everything 74 with an original factory cam and 8:1 pistons is doing fine on Mobil1 20w-50.
Thanks to all who helped.