Dry sump question

Greetings all,

I have a question on the dry sump system used on many Harley engines. I have a 95 Sporty, I have had it a few years now. Recently, the oil always seems low before I start it. It does have a slight leak on the engine, but nothing severe.

Recently I was away from home for a month, so no riding. I returned Sunday, and went riding yesterday. While doing the pre-ride checks, I noticed the oil was quite low, off the stick low. I added some to get it to the stick, and started the bike. Suddenly, the oil was too high! I had to siphon some out. I suspect that when the bike is sitting the oil is slowly leaking into the crankcase.

Is this normal? Is this something I should be concerned about? If I leave the bike sit over winter, and all the oil ends up int he crankcase, could that cause damage when I start it up?

Thanks for the help,
Panth

Thank HRK,

I know the actual check should be warm, but I like to first check before starting to make sure there is oil in it. A stitch in time saves nine, and verifying oil saves major engine repairs.

The amount of oil it took to get it to the stick was about a cup, just to the bottom of the stick, which saved me from having to siphon too much out. I was just worried that if too much drains into the crankcase, there might be too much crankcase pressure on starting.

Thanks for the help,
Panth

The Sporty oil pump is different than the Evo BT pump, but that happened to mine too after it sat all winter, that was over 15yrs ago and the bike has never been apart except for a street port and carb tweek. Here's a link to the oil pump schematic.
1995 Harley-Davidson XLH1200 OEM Parts, 1995 Harley-Davidson XLH1200 OEM Replacement Parts - BikeBandit.com

Yeah Chuck...Bike Bandit is a great site for schematics and hard to find parts for all years, makes and models.

Nope. The only time you have problems is when you top the tank off BEFORE starting the bike & many have had the oil cap / dipstick blow right off !

The fellas already pin-pointed the check valve problem & even brand-new it doesn't work all that well, so over time, oil will gradually drain down into the crankcase. But the oil pump "scavenges" well & if you start the engine & just let it idle for a bit, the pump will return the oil back to the tank & the recirculation process will start working right away.

Also, people often ask why they see air bubbles on top of the oil in the tank when the engine's running & the reason is that the pump can pull more oil out than is normally there, so it's sucking air too - those bubbles are normal.

So when you start the bike for the 1st time after it's been sitting for a while, leave the oil cap off & watch the level rise & the air bubbles form. Once the engine has run for a few minutes, then you can change the oil or add a little if necessary.

Great explanation, works on big twins too.