explain sumping please
Thread Starter
|
Road Master
Joined: Jun 2008
Posts: 1,192
Likes: 2
From: Sin City
explain sumping please
Getting that 2000 Ultra with the 96" S&S motor. Looking into the fixes and I keep reading about EVO motors and a possible sumping issue. What is it and how do you fix it? Is it anything like the scavenging issue with shovelheads? Is scavenging and sumping the same thing?
Seasoned HDF Member
Joined: Aug 2007
Posts: 8,198
Likes: 3,087
From: NW AR
Yeah, they mean the same thing. The cases fill up with oil if you let them sit, then puke out on the garage floor when you start it up. They almost all do it if you let them sit long enough. Fix? Well, depending on how bad, just leave it alone, or you can put a new ball in the oil pump, beat on the ball with a hammer, match the ball to the pump body with valve grinding compound, put a new oil pump on, etc. If it only does it if the bike sits for a few months, don't worry about it. If it does it every day, fix it.
Road Master
Joined: May 2009
Posts: 817
Likes: 1
From: N.E. Ohio
Mine used to put a little oil now and then. Lately it seems a little more than normal. It leaves a spot about the size of a half dollar coin sitting after riding it. Think I should fix it or let it go?
Seasoned HDF Member
Joined: Aug 2007
Posts: 8,198
Likes: 3,087
From: NW AR
That's not sumping, BB4xl. That's blow-by. Sumping is when you let it sit and start it up after a week and it pukes oil out the breather. Blow-by is when you go look under the bike the next day and there's a small spot.
Thread Starter
|
Road Master
Joined: Jun 2008
Posts: 1,192
Likes: 2
From: Sin City
Ahh .. ok so its not a engine running issue but a sitting issue. It was made to sound like a condition that the EVO motors could not get enough oil to the top end and it would pool in the lower end.
Club Member
Joined: Jun 2007
Posts: 45,429
Likes: 2,898
From: Bedford UK
Trending Topics
Seasoned HDF Member
Joined: Jun 2010
Posts: 9,332
Likes: 3,873
From: Upstate New York
Sumping occurs because the Harley carries its oil supply in a tank ABOVE the motor and oil pump inlet. The oil pump has a check valve which keeps the oil in the tank when the engine is not running. This valve is a ball and seat type valve, and on some motors, might not seal perfectly all the time. This allows some of the oil to "sump", or slip past the oil pump into the lower end.
On my bike, this is only an issue during winter storage, where the bike sits for three months. It's a pretty harmless condition, but the engine may spit some oil out the breather on startup, until all the oil gets back where it's supposed to be.
On my bike, this is only an issue during winter storage, where the bike sits for three months. It's a pretty harmless condition, but the engine may spit some oil out the breather on startup, until all the oil gets back where it's supposed to be.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Seasoned HDF Member
Joined: May 2008
Posts: 21,131
Likes: 12,691
From: South Carolina
Looks like we could have more than one definition of sumping..
Sumping is when the scavenge system cannot return oil back to the tank fast enough to prevent oil accumulating in the crankcase, for any number of reasons. In this case it does not matter if the oil tank is above or below the engine (when the engine is running).
Also when the oil drains past the check ball while the engine is not running, on a machine with the oil tank mounted above the engine.
So, would we call one Dynamic Sumping and the other Static Sumping?
Sumping is when the scavenge system cannot return oil back to the tank fast enough to prevent oil accumulating in the crankcase, for any number of reasons. In this case it does not matter if the oil tank is above or below the engine (when the engine is running).
Also when the oil drains past the check ball while the engine is not running, on a machine with the oil tank mounted above the engine.
So, would we call one Dynamic Sumping and the other Static Sumping?
Thread
Thread Starter
Forum
Replies
Last Post
