New GasGas guy confused on air leak

[Jazown]

Hey everyone!

I have a 2013 EC250 that I’ve recently brought back from the dead with a full rebuild. I have a problem with what I assume is an air leak as soon as the bike gets up to temp (idles at around 3000rpm). I’ve put about 15 hours on it so far and it’s been amazing until this issue.

I sprayed it down with brake clean, found no leaks. I smoke tested it through the intake and smoke pours out of the power valve vents, is this normal? I can’t see any form of seals in the parts diagram that should go in the power valve assembly. I assembled the power valve when I rebuilt the engine and there were no seals as far as i’m aware.

 

[swazi_matt]

there is an oil breather from the powervalve, so there must be some minor leakage through there - in fact i remember seeing my breather pipe smoke when cold. From the factory they used to fold the breather pipe over and ziptie it but i think that was just to avoid oil dripping on the trails causing pollution

 

[(F5)]

So is the cable hung up or something preventing the slide fully bottoming home?
That would make it fairly hard to start.

 

[Jazown]

So is the cable hung up or something preventing the slide fully bottoming home?
That would make it fairly hard to start.

I don’t think so. I can literally watch it happen while idling, it’ll just start picking up in rpm with no hands on any controls. Super odd!

 

[coopernicus]

Did you check the carburetor for air leaks? They get worn out over time...

 

[Jazown]

there is an oil breather from the powervalve, so there must be some minor leakage through there - in fact i remember seeing my breather pipe smoke when cold. From the factory they used to fold the breather pipe over and ziptie it but i think that was just to avoid oil dripping on the trails causing pollution

Thanks!

 

[Jazown]

Did you check the carburetor for air leaks? They get worn out over time...

I did, sprayed brake clean around it and smoke tested through it.

All I have is the power valve leak to go by. I’m wondering if the cylinder is slightly worn and not sealing properly to the bearing..

I clamped off the L/S drain and it didn’t make a difference. Just trying to figure out why the R/S has such a leak, I can’t see any seals in exploded diagrams besides spacers and bearings.

 

[(F5)]

So good point. The needle tower seal can leak I've heard . perhaps some petrol proof sealant would be a good idea to diagnose. Say Loctite master gasket. Don't use rtv etc.

 

[swazi_matt]

does your bike have a cable choke?:

 

[Jazown]

does your bike have a cable choke?:

It does not