Oil Level

[biscuit]

OK. Softail, or "B" motors left sitting will drain oil from the tank to the sump but that oil has to pass through the oil pump. Since the oil pump is not operating, the drained oil is under the "head" pressure from the oil tank above and will fill the oil pump cavity, flow past the feed and scavenge gerotors and drain into the sump from the scavenge side of the pump. There is a "wavy" washer between the feed and scavenge gerotors that is supposed to slow or prevent oil from the tank passing through; however, depending on factory tolerances, the wavy washer may not have enough tension on the gerotors to prevent oil from passing through which is why some softails drain oil from the tank faster than others.

Having said all that, it should be clear that people suggesting that drainage from a softail oil tank to the sump indicates a failure or fault of the oil pump don't understand softail oil flow.

A lot of softail owners that have to store their bikes for the winter use hose clamp pliers clamped to the short rubber hose just under the oil tank to prevent oil draining from the tank to the sump.

Aftermarket pumps like Fuelling, S&S etc. are supposed to have tighter tolerances to slow or prevent the drainage.. I have the S&S T3 setup on my 98" motor but id drains down, slower, but still drains into the sump.

Hope that helps.

Dolt, I thank you for your(typical) analytical reply.
I was aware that sumping was a thing that Softails suffer from-and that my Twin Cam doesn’t have that ball and spring check valve from earlier bikes that was meant to prevent it.
BUT I didn’t know the EXACT reason and whilst I didn’t think it was gloom and doom as per a lot of things I’d read; I WAS a little concerned- particularly as all my bikes ( only my H-D is a dry sump) haven’t been ridden for 20 months or so due to injury.
I had turned the motors over with a roller starter to at least circulate oil- but I know there’s no substitute for being used.
Again, thanks for the response. As always, I find your replies to be well thought out and informative.

 

[dolt]

A softail that has not been ridden for a while should be started and let idle for several minites. Best way to insure all the oil from the sump has been scavenged and in circulation would be to remove the oil tank cap and watch until a steady robust stream of oil is being pumped back into the tank. This could take 5 minutes or more depending on how much oil has drained to the sump. Then check oil level and add if necessary.