What does it mean to have oil leaking from your exhaust header? Added pic for reference.

This is a new issue that has just arrisen. As well as smoke (maybe blue, i cant tell. But the oil would explain that) from the tail pipe and the bike stalling. This is only on the left side.

Also on the left side, the carb float seems to be sticking. When i set it to prime, there is a leak. But here is the weird thing, the leak is coming from the vacuum line that runs above the air box and down between the air box and battery. I dont how how gravity is sending it that way?? The leak isnt comung from the air box drain hose like it usually should with a stuck float problem...

Help!

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1. that's a valve-cover gasket leak, or maybe the breather gasket leaking, I think
2. the hose you refer to may not be a vacuum hose. You could be talking about a vent tube, the purpose of which is to allow vapors (and fuel, I suppose) to escape.

Quote from: mr72 on July 25, 2017, 02:33:07 PM
1. that's a valve-cover gasket leak, or maybe the breather gasket leaking, I think
2. the hose you refer to may not be a vacuum hose. You could be talking about a vent tube, the purpose of which is to allow vapors (and fuel, I suppose) to escape.

1) How big of a job is this to replace?

2) You're right, it is the vent hose not vacuum. Where would the gas be coming from to send it there? And why does it happen when set to prime?

There is way too much going on with this bike. It's like something else happens every time I ride it....

Check carefully the torque on the Allen bolts holding the exhaust itself to the head. They sometimes get loose.

Quote from: Rallyfan on July 26, 2017, 08:35:54 AM
Check carefully the torque on the Allen bolts holding the exhaust itself to the head. They sometimes get loose.

But is it even supposed to have oil there?

Quote from: Shift-E on July 26, 2017, 08:40:35 AM

Quote from: Rallyfan on July 26, 2017, 08:35:54 AM
Check carefully the torque on the Allen bolts holding the exhaust itself to the head. They sometimes get loose.

But is it even supposed to have oil there?

No, but as mr72 said, it looks like your valve cover gasket is leaking, not the actual header gaskets. Oil probably isnt leaking FROM the header gasket (as there should not be oil there), the oil is probably coming from the valve cover gasket and then flowing down to the headers.

My exhaust itself was loose. The bike looked like yours. That's why I suggest you check the torque on the exhaust bolts.

Another suggestion: check the torque on the exhaust bolts.

I mean, checking the torque on those bolts wouldn't be a bad thing to do, but I don't think you can have an oil leak from there, even if the exhaust is loose.

As far as I'm aware, the biggest issue with a loose exhaust is that the hot exhaust gasses that leak out can damage the exhaust ports over time.

Quote from: Shift-E on July 26, 2017, 08:31:33 AM
1) How big of a job is this to replace?

Remove tank, remove valve cover, remove old gasket, put new gasket, reinstall valve cover (with torque wrench etc...), reinstall tank. Probably a 30 minute job if you know what you are doing, an hour if you don't.

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2) You're right, it is the vent hose not vacuum. Where would the gas be coming from to send it there? And why does it happen when set to prime?

The gas comes from the float bowls, essentially. It does this when on prime because fuel is allowed to flow into the float bowls, it's an indication that your float needle valves are worn or sticking. It's quite common. You shouldn't park the bike with it on prime. The float needle/seat would have to be in mint condition to not leak at least a little bit, and with modern fuels and ethanol etc. the brass seat for that valve is almost guaranteed to become corroded making a perfect seal basically impossible. So the solution is: don't park the bike on Prime. use prime just to start it after you've drained the float bowls for other service.

BTW if it's leaking fuel from there it is flooded (most likely) and there may be liquid fuel in the cylinders, so you should exercise caution when trying to start it back up so you don't hydrolock (take plugs out, crank it, ensure fuel can escape, etc.).

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There is way too much going on with this bike. It's like something else happens every time I ride it....

It's not issues with the bike. I mean a minor oil leak at the valve cover is pretty routine and common maintenance and leaving it on prime is almost guaranteed to result in this fuel overflow.

Quote from: mr72 on July 26, 2017, 11:04:09 AM\

The gas comes from the float bowls, essentially. It does this when on prime because fuel is allowed to flow into the float bowls, it's an indication that your float needle valves are worn or sticking. It's quite common. You shouldn't park the bike with it on prime. The float needle/seat would have to be in mint condition to not leak at least a little bit, and with modern fuels and ethanol etc. the brass seat for that valve is almost guaranteed to become corroded making a perfect seal basically impossible. So the solution is: don't park the bike on Prime. use prime just to start it after you've drained the float bowls for other service.

BTW if it's leaking fuel from there it is flooded (most likely) and there may be liquid fuel in the cylinders, so you should exercise caution when trying to start it back up so you don't hydrolock (take plugs out, crank it, ensure fuel can escape, etc.).

Right, this much I knew. But my understanding is that it would usually come out from the airbox drain hose, not the vent hose above the airbox. What kind of conditions would cause it to come from above and not the point that makes the most sense when taking gravity into account?

The carbs were cleaned recent, and the needles are new. I did, however, park it once on prime recently by accident. Thankfully there was no issue with leaks. However, a few days later there were leaks on prime (i've been riding on reserve though). Would it make sense for the needles to go bad that soon?

I've flushed the cylinders recently, but will do it again to double check they didn't flood again.

Quote from: Shift-E on July 26, 2017, 11:31:49 AM
But my understanding is that it would usually come out from the airbox drain hose, not the vent hose above the airbox.

It'll come from whatever fuel outlet is below the level of the fuel tank.

When the fuel overflows the float bowl it just goes wherever there is an opening for it to go. I can't say what the passageway is above the float bowls but clearly this hose is connected in order to allow gases to vent. There also must be a way (perhaps through this hose) for air to flow in to the top of the float bowls to displace fuel that is spent in the process of running, and also to provide something close to atmospheric air pressure on the top of the fuel in the float bowl, which is the pressure that actually "pushes" fuel up through the jet(s). Forgive me, I don't have a carburetor in my hand right now to go snake the vent outlet and see exactly where it winds up in the float bowl but this is sensible.

Quote from: qcbaker on July 26, 2017, 10:27:55 AM
I mean, checking the torque on those bolts wouldn't be a bad thing to do, but I don't think you can have an oil leak from there, even if the exhaust is loose.

As far as I'm aware, the biggest issue with a loose exhaust is that the hot exhaust gasses that leak out can damage the exhaust ports over time.

Sorry I can't make this clearer: I have experienced an apparent oil leak due to those bolts being loose.

It's an empirical question frankly. If you are in doubt, loosen the bolts and drive the bike.

The symptoms will mimic an oil leak as depicted.

So Rallyfan was definitely on to something. One of the bolts was loose. Tightened it up and cranked the bike. No leaks. This is odd to me. I wouldn't think there should be oil in that area.. I guess there is? I'll just take it as it is lol

I would welcome an explanation from someone much more knowledgeable than myself. How does one get an oil leak from the exhaust port? If there were oil there to leak out, wouldn't the bike be burning oil?

Yeah one way for oil to get there is if the valve stem seals are leaking, oil would make its way down the exhaust valve and potentially leak out the exhaust port (and also into the combustion chamber). My theory would be for the oil to leak while the bike is parked. If the exhaust valve is closed when it's parked then the oil would have nowhere to go but the exhaust port. On startup you'd blow/burn it out anyway.

So the bike may be "using" oil but not "burning" so much of it in the traditional sense. It's leaking, just internally, into a place where it will get expelled.

Just a guess. Does seem odd to me for sure.

Quote from: mr72 on July 31, 2017, 08:18:24 AM
Yeah one way for oil to get there is if the valve stem seals are leaking, oil would make its way down the exhaust valve and potentially leak out the exhaust port (and also into the combustion chamber). My theory would be for the oil to leak while the bike is parked. If the exhaust valve is closed when it's parked then the oil would have nowhere to go but the exhaust port. On startup you'd blow/burn it out anyway.

So the bike may be "using" oil but not "burning" so much of it in the traditional sense. It's leaking, just internally, into a place where it will get expelled.

Just a guess. Does seem odd to me for sure.

This would actually make lots of sense. I think one of my spark plugs may have some oil sprayed on it when I crank. Wasn't sure if it was excessive gas or oil, didn't examine closely. 2 brand new spark plugs, and that one looked wet and basically new compared to the other one that was a little darker with maybe some soot on it (maybe indicative of something but I dunno how to read them properly, even when comparing them to images)

Quote from: Shift-E on July 31, 2017, 07:55:53 AM
So Rallyfan was definitely on to something. One of the bolts was loose. Tightened it up and cranked the bike. No leaks.

I'm glad to hear this. Sorry for being a bit blunt above but I knew precisely the symptoms and cure.

QuoteThis is odd to me.

You should see me in person... Heh...

Cheers!