fluid spitting from exhaust

Hey everyone. Today I noticed that my 81 kz550 was spitting what looks like oil out of a hole in the left exhaust pipe. The right side is fine and there's nothing coming out of it. The bike does not run on the #3 cylinder. Does anyone know what might cause oil to come out of the left pipe?

nickleo373 wrote: Hey everyone. Today I noticed that my 81 kz550 was spitting what looks like oil out of a hole in the left exhaust pipe. The right side is fine and there's nothing coming out of it. The bike does not run on the #3 cylinder. Does anyone know what might cause oil to come out of the left pipe?

Would suspect that the substance escaping from the exhaust pipe hole is gunge from inside the combustion chamber of the non-combusting #3 cylinder. A mixture of gasoline, carbon (soot), and perhaps also a little oil.

When whatever is causing the combustion failure has been corrected so that the engine is firing on all cylinders, the substance from the hole will probably be drier and look more like carbon.

Good Fortune!

Thanks Patton. Should the exhaust system be replaced if it haa a hole? I'm not sure if that would effect performance

What size hole, and where located -- in header pipe or muffler or collector?

A photo might be helpful.

A small pin-hole should not itself diminish engine performance.

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Its about the size of a small nail. Its located where the muffler connects to the rest of the pipe. I'll take a picture when I get home

nickleo373 wrote: Its about the size of a small nail. Its located where the muffler connects to the rest of the pipe. I'll take a picture when I get home

Would doubt that the hole has any effect on engine performance, and that the hole most likely isn't related to the non-combustion issue.

The hole could probably be sealed with a dab of JBWeld.

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If the hole is on the underside, it may be there to allow water to drain. My 81 650 has drain holes.

martin_csr wrote: If the hole is on the underside, it may be there to allow water to drain. My 81 650 has drain holes.

+1 The drain holes should be kept open to prevent condensation from collecting in the exhaust and causing rust. Ed

The bike is being stored in a climate controlled garage so it's unlikely it was exposed to water. The fluid doesn't smell like gas and is a yellowish color like oil. Is it normal for it to drain oil through the holes?

nickleo373 wrote: The bike is being stored in a climate controlled garage so it's unlikely it was exposed to water. The fluid doesn't smell like gas and is a yellowish color like oil. Is it normal for it to drain oil through the holes?

No. Oil shouldn't be getting into the exhaust system. It may be coming from that #3 cylinder that isn't firing. I would take a look at the #3 plug to see if it is oily. Ed

I'll look at it. Thanks Ed

nickleo373 wrote: Hey everyone. Today I noticed that my 81 kz550 was spitting what looks like oil out of a hole in the left exhaust pipe. The right side is fine and there's nothing coming out of it. The bike does not run on the #3 cylinder. Does anyone know what might cause oil to come out of the left pipe?

If it's a factory provided drain hole that's supposed to be on the underside of the left exhaust pipe, would expect there to also be a matching drain hole on the underside of the right exhaust pipe.

Such drain holes should be kept open to freely discharge water from condensation formed inside the exhaust system.

Would not expect water to spontaneously form inside the exhaust system while parked inside a climate controlled garage or anywhere else.

From the wonderful world of Yahoo:

You need to run the vehicle long enough to let the pipe get hot, which stops the production of condensation. When the exhaust is hotter then the inside surface of your exhaust system, you produce condensation. That causes condensation every time you start up the vehicle, in cold weather, you produce more. If you run the engine long enough, it will empty the water from the low lying areas, which is why you should not just jump into your vehicle in the winter, drive 1 mile and stop it. That will rust out your exhaust quickly. In the summer, you produce less condensation because the pipe and the exhaust stay at a closer temperature which produces less condensation.


The yellowish color oil-like substance might possibly be oil from the cam area that's seeped past worn exhaust valve stem seals and drained through the exhaust port into and down the inside of the header pipe.

When parked on the side-stand, tilted to the port side, oil in the cam area collects toward the #1 exhaust valve, which would tend to produce more seepage through the #1 exhaust header.

Good Fortune!