Exhaust gases from breather

[Gasserxxx]

Hi all, I am a newbie here and am on the verge of buying my first Gas Gas EC, the 250cc version. However when I viewed it I noticed that the breather from the RHS powervalve cover was blowing alot of blue exhaust smoke and wondered is this normal or does it indicate engine problems??

I have uploaded an image to assist in identifying which pipe it is.

Thanks in advance!

 

[Jakobi]

How much is alot? The tube off the rhs powervalve is the breather for the clutch and gearbox, but some gasses could still be passing through the PV bearings.

Has the bike been using tranny fluid?

 

[Gasserxxx]

Hi, it is a bike I am looking to purchase so I dont know ref the tranny fluid. When the bike was running there was alot of exhaust fumes coming from this pipe, as if it was tapped off the exhaust itself!?

Could this be the PV bearings then? If so are they expensive to replace?

Thanks for your help!

 

[Jakobi]

I've never seen mine blow any smoke. I imagine if the pri side main seal was gone you could get positive crank pressure pumping out of this, but you would likely also be pulling transmission fluid into the crankcase and everything would be spooging and smoking like crazy.

The PV does allow some exhaust to pass into the chambers on both sides though as there will always be some build up on the covers. The LHS PV hose will drain excess spooge.

I'd probably not be too concerned about it on its own, but rather look/listen to see if the bike is showing any other issues which could indicate a problem.

 

[Fred1956]

Is the RH PV bearing sealed? If someone put an open bearing in it would leak exhaust?

 

[Gasserxxx]

Hi all, many thanks for your replys, really appreciated! I went ahead and bought the bike and after a quick run the smoke wasnt aoppearing unless I revved it really hard. Maybe it just needed a blast to get it warmed up?? At least it doesnt seem to be an issue at the minute!

Just need to get it to tick over now and get a sidestand!!

Thanks again!!

 

[motopsycho87]

It's fine, all 2 stroke smoke when cold, and only a little when hot. It just means there is a little blow by on the right hand power valve bearing, don't worry about it.

 

[imsimon]

My 250 does the same but not loads and always stops once warmed up. I initially thought it was coming from exhaust so changed gasket etc and then realised it was the breather!