Oil Spot - Is that normal

[Bert2006]

After extended rides (1h or more) I get a small amount of oil coming out of the tube right behind the kik stand. It is just enough to mark the concrete on the garage. Very dark and oily. Other than that not other leaks anywhere that I can see.

 

Thanks

 

[BuddyRich]

If your over half on the sight glass then it may be too high. If your seeing it for sure come from that tube it should be engine oil. But if you check the bottom of the rear shock and it has oil on it you could be losing your shock. They both dump in about the same spot but I think the shock oil was not so black when I lost mine

[steamer]

Its only normal for HD's

[friesman]

Oil spots aren't normal, As Buddy said, its probably your oil overfilled. No more than halfway up the sight glass when the bike is upright, NOT on the kickstand. Also, the manual seems to ask to add too much oil by about 1/2/quart.

 

Brian

[V7Goose]

Actually, this IS normal (but there are a few qualifiers to that statement).

 

The oil is coming from the vent tubes on the air plenums (the boxes above the carbs), and it is why you also see an oily grunge on the tip of your side stand. And this is also related to why the #1 carb is always covered with oily dirt on a Venture that is ridden a lot. The crank case breather connects between the two plenums, so oil mist from inside the engine is normally sucked back through the carbs and burned, but a fair amount will stick to the inside of the boxes and slowly work its way down the sides and towards the drain at the back of the plenum. Hard fast long runs generates lots of oil mist, and a bit of it eventually works its way out those drain hoses, exactly like is is designed to do.

 

Now, if you over-fill your crank case with oil - defined as ABOVE the sight glass, not just above mid glass, seeing any air bubble above the oil is just fine - this engine will pump a LOT more oil mist our the vent and you will get significant dripping through those vent hoses, resulting in more than just a drop or two after a long run. And once that starts, it is hard to ever get it completely cleaned out. Those vent tubes have check valves in them so the carbs cannot suck dirty air up from the road, and those check valves tend to make it difficult for all the oil mess in the vent lines to fully drain out, resulting in on-going drips even after the over-fill is corrected.

 

Now about that oil mess on the #1 carb - that is a result of a very STUPID design flaw. The air plenum drain tube is located at the inside rear point of each air plenum. That point is the lowest point for both when the bike is upright, but NOT when the bike is on the side stand! When it is leaned over to the left, the drain for the plenum above the left side carbs is HIGHER than the top of the carbs. And since just about all bikes spend more time sitting on the side stand than running upright, most of that oil mist that collects inside the air box eventually works its way down around the top of the left rear carb. Over time, a lot of it oozes out of the rubber fitting round the top of the carb and spreads like a toddlers nose goo down around everything below it, collecting dirt, bugs and other ugly crud!

 

Goose

[Bert2006]

Actually, this IS normal (but there are a few qualifiers to that statement).

 

The oil is coming from the vent tubes on the air plenums (the boxes above the carbs), and it is why you also see an oily grunge on the tip of your side stand. And this is also related to why the #1 carb is always covered with oily dirt on a Venture that is ridden a lot. The crank case breather connects between the two plenums, so oil mist from inside the engine is normally sucked back through the carbs and burned, but a fair amount will stick to the inside of the boxes and slowly work its way down the sides and towards the drain at the back of the plenum. Hard fast long runs generates lots of oil mist, and a bit of it eventually works its way out those drain hoses, exactly like is is designed to do.

 

Now, if you over-fill your crank case with oil - defined as ABOVE the sight glass, not just above mid glass, seeing any air bubble above the oil is just fine - this engine will pump a LOT more oil mist our the vent and you will get significant dripping through those vent hoses, resulting in more than just a drop or two after a long run. And once that starts, it is hard to ever get it completely cleaned out. Those vent tubes have check valves in them so the carbs cannot suck dirty air up from the road, and those check valves tend to make it difficult for all the oil mess in the vent lines to fully drain out, resulting in on-going drips even after the over-fill is corrected.

 

Now about that oil mess on the #1 carb - that is a result of a very STUPID design flaw. The air plenum drain tube is located at the inside rear point of each air plenum. That point is the lowest point for both when the bike is upright, but NOT when the bike is on the side stand! When it is leaned over to the left, the drain for the plenum above the left side carbs is HIGHER than the top of the carbs. And since just about all bikes spend more time sitting on the side stand than running upright, most of that oil mist that collects inside the air box eventually works its way down around the top of the left rear carb. Over time, a lot of it oozes out of the rubber fitting round the top of the carb and spreads like a toddlers nose goo down around everything below it, collecting dirt, bugs and other ugly crud!

 

Goose

 

 

Thanks for the great explanation. I checked last night and oil level is between half and

3\4 of the sight glass (with bike level). Will make sure that I pay attention to not adding too much at the next oil change.

[Phoneman1981]

Welcome to the site. I too have had this happen to me. You are not alone. So much knowledge.

[rlweaverventure]

Thanks for that great explanation- I just took mine off to clean up the oily residue mess and was wondering if maybe I had too much blow-by. The left side was all that was messy and the left rear the worse by far!

[Carbon_One]

Thanks for that great explanation- I just took mine off to clean up the oily residue mess and was wondering if maybe I had too much blow-by. The left side was all that was messy and the left rear the worse by far!

I'd say that's what one normally finds to be the case.

Goose gave an excellent explanation.

Larry

[crazygaucho]

I was reading some old post trying to get some info in the subject and ,

I think I'm guilty of adding a little too much oil in my bike and it is leaking from the breather .............. my question is :

will I hurt anything if I leave like this until next oil change ?

or you suggest to drain the extra oil?

I think it is not much.

thanks in advance

Dan

[bongobobny]

Well, I guess that depends on whether or not you like cleaning up oil messes! As far as harm to your engine, no, not really...

[CaptainJoe]

I overfill mine on purpose..

 

Steve and Ray, the guys I ride with, have Harleys...

 

I just didn't want them to feel bad..

 

The things a guy has to do to keep his buds happy...Jeeeeeeesh!

[Yammer Dan]

HEY FREEBIRD....question for you.

[crazygaucho]

Well, I guess that depends on whether or not you like cleaning up oil messes! As far as harm to your engine, no, not really...

isn't that big of a mess just about the size of a quarter overnight plus I park outside (no garage) covered of course.

[bryan52577]

THANKS V7GOOSE!!!

Here the past 5 years, the whole time I have owned my Venture. I have been telling everyone that is a "Harley sympathy tube". Now I have to tell them the truth.

Bryan