Causes of oil on bottom of motor

[mv60564]

Looking at a '99 interstate and noticed a significant amount of oil residue on underside of motor towards the front.  No oil under bike though.  My '97 standard is bone dry in the same spot and am wondering what some of the more common causes could be and whether I should be really concerned or just a little concerned.....appreciate any advice anyone might have...

[Joevalk]

Gear shaft seal is a common oil leak for high mileage valks. Easy fix.

[Tfrank59]

If you can, be more specific and take a closer look for the source area--is it near the oil filter, the area near where the cases meet, somewhere else or as Joevalk said near the gearshift area?  If it's not enough to drip on the floor, it's not too big a deal but you can, and should, figure out the cause.  Sometimes cleaning everything spotless first will clearly show the leaky spot. 

[John Schmidt]

Could also be from the weep hole at the bottom of the water pump, time for a new pump if so.

[cookiedough]

It has happened in car, but could on our Valks as well.  Oil filter not tight enough spun on or overtightened and the outside rubber o-ring on the filter cracked allowing a few drips out daily then running back behind the oil filter on bottom of engine? 

Like said, a quick thorough cleanup of the area where oil is present might be able to then see where it is coming from if keep a close eye on it for awhile?

[Ricky-D]

It could be, simply oil left to remain on the engine, from previous oil changes.

The best advise has been stated by Tfrank59.

Clean everywhere under the engine and then observe on a regular interval.

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[The emperor has no clothes]

It could be, simply oil left to remain on the engine, from previous oil changes.

The best advise has been stated by Tfrank59.

Clean everywhere under the engine and then observe on a regular interval.

***

I think he's looking to buy the bike. At least that's the way I took his post. I think it's probably just sloppy oil changes.

[Jess from VA]

After a few years the bottom of my engines get pretty cruddy (with no leaks or spills).  I use a can of engine degreaser or S-100, scrub with a brush, and rinse it off (back to sparkling).  I try to do this in someone else's driveway (or the street).