Diagnose sumping : V-Twin Forum: Harley Davidson Forums

jam65 · 10-30-2009, 08:51 PM

What do you look for to determine if sumping is being a problem?Also how many ounces of residual oil left in engine is a determining factor?

TXCHOP · 10-30-2009, 09:48 PM

Get the motor good and warm. I like to take a short trip of at least a few miles.
Get home and pull the pipe plug on the bottom of the cases. Let the oil drain into a measuring cup to see how many oz's are in there. Usually 4-6-8ish in there which should be o.k.

Usually when a motor is sumping it will run hotter and feel really sluggish and may even sound different. It can clear up and go away though.Usually repeat roll ons will tell ya..
Careful with the plug and do not over tighten...

jam65 · 10-30-2009, 10:42 PM

Thanks Chop,I still need a couple more heat cycles before road test.Does a higher lift cam make more left over oil more acceptable?

aharp · 10-31-2009, 08:08 AM

I had a brand new 07 FXSTC come in for a 1k. Checked the charging system and I'll be damned, something didn't feel right. It came down of the rev's VERY fast, sluggish like TXChop said. Hold it wide open in neutral and it couldn't pass 4k. Pulled it all apart to find that the factory never drilled the oil pump passage that scavenges the flywheel compartment

They guy got his bike bike and couldn't believe how much better it ran

TXCHOP · 10-31-2009, 08:29 AM

Holy $hit aharp, QC at its best. Good find though..

And no, Jam, cams don't change the amount allowed.

aharp · 10-31-2009, 08:36 AM

Quote:

Originally Posted by TXCHOP

Holy $hit aharp, QC at its best. Good find though..

And no, Jam, cams don't change the amount allowed.

Yes, tricky one indeed

It didn't make me feel any better when my rep from the moco said "oh yeah, guys find stuff like that all the time"

TXCHOP · 10-31-2009, 12:35 PM

Jam are you concerned about sumping? Unless you are, dont worry about it. As long as you got the assembly down, you should be fine.

01fxdx · 10-31-2009, 12:53 PM

for what it's worth, when i ran into sump issues, the oil temp got rediculous.

Coolmaker · 10-31-2009, 01:11 PM

Quote:

Originally Posted by 01fxdx

for what it's worth, when i ran into sump issues, the oil temp got ridiculous.

That is because it aerated, mine did the same thing..

Bigtwin101 · 10-31-2009, 04:00 PM

what causes sumping? sometimes my bike is sluggish between 2500 and 3000 rpm. I have 248 degree oil on a 58 degree day

DRG · 11-01-2009, 06:01 AM

Had a bad piston oiler. I was dumping 20 oz. out the crankcase.

kemo · 11-01-2009, 06:25 AM

If you had the cams changed and you suspect sumping was the oil pump aligned when they put it back together.
kemo

reg26 · 11-01-2009, 06:55 AM

What is the "pipe plug" on the bottom of the cases and what is it used for besides checking for sumping. Been wondering about all this sumping talk.

ultraplusrotax · 11-01-2009, 01:20 PM

The pipeplug is a plug at the lowest part of a rubber hose coming down from the seperate oiltank, as seen on Sportsters and Softails.
When changing oil you have to remove the plug so that the oiltank is drained, and of course, after the tank is empty, replace the plug in the hose before filling up the tank.
Touring models , not having a seperate oiltank, do not have that pipeplug: their oil is contained behind the transmission, and can be drained by removing a hexagon steelbolt.
"Sumping" is the accumulation of oil in the crankcase, where it shouldn't stay in a DRY SUMP system like in H-D engines.

HugoBetz · 11-02-2009, 06:43 AM

Quote:

Originally Posted by ultraplusrotax

The pipeplug is a plug at the lowest part of a rubber hose coming down from the seperate oiltank, as seen on Sportsters and Softails.
When changing oil you have to remove the plug so that the oiltank is drained, and of course, after the tank is empty, replace the plug in the hose before filling up the tank.
Touring models , not having a seperate oiltank, do not have that pipeplug: their oil is contained behind the transmission, and can be drained by removing a hexagon steelbolt.
"Sumping" is the accumulation of oil in the crankcase, where it shouldn't stay in a DRY SUMP system like in H-D engines.

The pipe plug is at the bottom of the case half just below the cranks shaft. I checked mine for sumping and got about 3 ounces of oil. If you were anal about changing oil you could drain the little bit of oil from there at normal change intervals. It's not necessary as only a few ounces are there normally.