Oil out the breather...

[yessum]

.. or, what looks to me like a breather. It's a gap in the side of the crankcase about 4 or 5 inches above the oil pan, with an area of a few square cm.
After a ride, oil is streaming down the side (from this gap) and over the waterpump, ending up pooling on the bottom and dripping substantially.
Oil has never been overfilled, is now quite close to the "Low" mark, and is continuing to drip out during a ride.

I have reliable sources telling me from their experience that this indicates worn piston rings pressurising the crankcase, but I would like some input from motorcyclists.
Should i get a compression check?
Should i be seeing oily smoke out the exhaust?

(bike is an '85 suzuki 250cc four cyl, 65,000km)

This is pissing me off

[merv]

The bikes I ride have some sort of tube on the crankcase breather and it would take a bit for the oil to actually get out there. Is your bike meant to just have a "gap" or has something fallen off?

If not then chances are your engine is getting a bit worn but usually the engine would show smoke out the pipe particularly if you throttle off to slow down and then gun it. Generally engines have to be pretty sick before they start blowing oil out the breather in a big way.

[yessum]

yeah as I inferred i'm not sure exactly what I'm looking at. It could be that I've overlooked the real breather (in tube form?) and am talking about something else. I'll try to post a pic at some stage. All I know is that oil is streaming out of this particular "gap".

Thanks for your input

[pete376403]

On my GS the breather is a tube attached to a plate at the top of the engine (cam cover) and this is connected to the air filter housing (engine side of the air filter)
No modern bike will vent crankcase fumes directly to the atmosphere - that sort of thing went out with brit 650s.
Sounds like something has fallen off/loosened/broken. It needs looking at right now.

[Jackrat]

On my GS the breather is a tube attached to a plate at the top of the engine (cam cover) and this is connected to the air filter housing (engine side of the air filter)
No modern bike will vent crankcase fumes directly to the atmosphere - that sort of thing went out with brit 650s.
Sounds like something has fallen off/loosened/broken. It needs looking at right now.

Oh dear my bike vents directly into the atmosphere,Does this mean she's not modern,, Ummmm,no need to answer that
And yeah mate have it looked at now,Petes right there's some thing very wrong going on there.

[merv]

Don't worry JR the dirt bikes I have owned all vent to atmosphere. The last Honda I had was fitted with a little valve thingy on the end of the tube, my latest super duper Yamaha just has a straight tube hanging down the front of the engine and I'm thinking gee that's weird. The concern with dirt bikes is that they don't suck in water when you go through rivers.

I look forward to yessum's pic to see where on the engine the oil is leaking.

[FROSTY:Me]

Where are you dude?
Possibilities include
.-A blown gasket somewhere pumping oil straight out
.-the abovementioned worn motor (unlikely with that sort of quantity of oil )
-breather tube has come adrift-
airbox oil filter oillogged and actually sucking the oil out of the motor
Could you take a picture of the culprit area?

[MacD]

On this Suzuki250Fours website there is a link to a Yahoo! Group where you can supposedly download a GF250/GS250F service manual. You need to set up a Yahoo! account first if you don't already have one to get access to the group.

The manual should help you work out whether something is missing!

[yessum]

Thanks folks, although i wish the news was better.
I will try and get a pic at some stage, as it doesn't sound like what i'm talking about is a breather and I'm just confusing people :eyepoke:

Thanks MacD I found that one not long after I got the bike. Unfortunately, for the GF it only contained service data.

[Redstar]

It's rather strange that this is happening without loss of performance?
oil leaking under the water pump would be just the pump seal? engine side?
but above thats odd? My bike has an air filter vent with a clamp on the end It collects the filter oil plus condensation and periodically the clamp it supposed to be opened then reclamped othewise it sucks air bypasses the filter.
I would test the compression first and check the waterpump seal