Is this the dreaded sumping
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Intermediate
Joined: Apr 2021
Posts: 25
Likes: 1
From: UK
Is this the dreaded sumping
I have a 2019 117CVO FL that I bumped to 128ci a few years ago, new plate, pump, cam and heads. Its been running like a raped ape for the last 25k miles.
I pulled the sump plug while doing an oil change (having warmed up the motor) at the weekend to see about 600ml (20floz) drain from the hole, un-airated no bubbles or froth.
Its an S&S pump on a 3tho runout so you'd hope its scavenging ok.
It's already got vented dipstick, trans cover and head breathers vented to atmosphere
I plan to check:
David
I pulled the sump plug while doing an oil change (having warmed up the motor) at the weekend to see about 600ml (20floz) drain from the hole, un-airated no bubbles or froth.
Its an S&S pump on a 3tho runout so you'd hope its scavenging ok.
It's already got vented dipstick, trans cover and head breathers vented to atmosphere
I plan to check:
- Leakdown (pushrods off to check all points of the stroke), If suspect inspect valves and rings, new rings in hand so will probably replace and set closer to 'race'.
- Cam chest and pump etc
- Breathers (new Feuling set in hand)
- Oil return lines
- Cam chest check valve replace
- Sump plug replace (Feuling in hand)
- Piston oilers (they were replaced on the rebuild with pressure-tested and surfaced sets on Cometic gaskets as the S&S versions weren't released at that time) test and replace with S&S
David
Road Master
Joined: Jun 2013
Posts: 1,057
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From: Sarasota Florida
Seems that if it was sumping you'd have the associated power loss. Plus you have an S&S oil pump which eliminates any stock harley pump issues.
But you should talk with a trusted mechanic and discuss your concerns.
But you should talk with a trusted mechanic and discuss your concerns.
Seasoned HDF Member
Joined: May 2008
Posts: 21,032
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From: South Carolina
Well, the latest design OEM oil pump will pump enough oil and will eliminate sumping (on a healthy engine).
Not necessarily, that depends on what configuration of the S&S pump is in the engine.
Not necessarily, that depends on what configuration of the S&S pump is in the engine.
Last edited by Dan89FLSTC; May 15, 2025 at 09:19 AM.
Road Warrior
Joined: Sep 2016
Posts: 1,887
Likes: 1,059
From: SE Washington
Said you removed the sump plug? Should be removing the crank position sensor and checking amount of oil, if any, comes out from there. You'd definitely notice power loss if you truly have an issue. With the mods you have, I wouldn't worry at all if it's running good.
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Intermediate
Joined: Apr 2021
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From: UK
It was the CPS that I removed, I'm swapping out the sump plug as a matter of routine (Feuling short #765.
There was a small but noticable loss of power afetr I beat on it for 20 miles or so chasing a KTM, thats how I detected the issue.
There was a small but noticable loss of power afetr I beat on it for 20 miles or so chasing a KTM, thats how I detected the issue.
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From: poway
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