Sumping: What are the symptoms?
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Grand HDF Member
Joined: Jan 2012
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From: Oklahoma
Sumping: What are the symptoms?
My buddy has a new '18 Street Glide and I mentioned to him to watch for sumping with the M8 engine. His first question stumped me, how can he tell when it is happening? I assume a drop in oil level on the dipstick would be one way, but if it begins while riding, how will he know?
Road Master
Joined: Jul 2010
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From: Centeral Coast, California
It'll feel like his crank is filled with gum, and he'll literally have about 50% of his expected power as he rolls the throttle under load. It will be unmistakable that he has a real problem should it happen. Another description would be that it will feel like a motor that has had the compression released while running. It feels bogged down.
Last edited by gipper; Oct 16, 2018 at 12:59 PM.
Road Warrior
Joined: Sep 2016
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From: SE Washington
When it became obvious on my 17, it lost power going uphill into a headwind. Couldnt hold speed in 6th or 5th, and barely in 4th. Pulled over and checked the oil, but found nothing on the stick. After letting it sit for about 10 minutes, I started it and let it idle for about a minute... oil level was back to halfway between full and add.
Club Member
Joined: Jun 2007
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From: Bedford UK
Yes. I've never suffered it with a Harley, but did some years ago with an old bike. Under normal conditions the crankshaft spins in the crankcases, enjoying a permanent shower of oil mist. Sumping starts to fill the crankcase with oil, so the crankshaft is partially submerged in oil - a bit like us wading through water! The more the oil level builds up the greater the drag on the crankshaft, which could easily come to a halt. The poor thing has the life drained from it.
Tourer
Joined: Sep 2011
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From: naples fl.
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Club Member
Joined: Jun 2007
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From: Bedford UK
I agree it should be unlikely, however there are reports of them doing just that.
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Seasoned HDF Member
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From: San Diego, CA
But there is a difference between worrying about something and being informed. Knowledge is power. Since there IS the possibility, and the results can be a major hassle, it's wise to know the symptoms....
