Discussion in 'Mechanics Garage' started by Frank Ferich, Sep 6, 2021.
My Honda vfr800 interceptor 1999 has started to dripp oil soon as I start the engine
You are going to need to remove the fairings and find out where it's dripping from.
Absolutely the only way!
Thread title states that the oil is coming from the exhaust.
Are you sure that it is oil? I can imagine it being water vapor that is blackened by the exhaust deposits.
If it dries up after a while, it's water vapor and you need not worry,........ unless it continues long after the motor reaches operating tempiture. If that happens then you may have a head gasket leak (or some other major issue) in which case you would smell the coolant vapor in the exhaust.
If, however, it truly is oil, then you may have a stuck ring or two on a piston. A compression test of each cylinder should tell you which one.
Spot on. Its an easy mistake to make when the temperature turns colder around now. Or if the hole in the can has recently been cleared of debris.
The original cans have a tiny hole drilled at the lowest point of the shroud. This is where you should see the drips first.
By volume most of the "fumes" are water vapour. When they hit the cold silencer/muffler metal they condense and drip down to the lowest point of the structure, inside the surrounding can.
The drips collect particles of carbon soot on the way. To avoid the can rusting out at this point Honda drilled that drain hole to let the water out.
If I start mine in the garage, I always stick an old plastic ice cream tub beneath the lowest part of the can, as the dripping output is full of fine sooty carbon deposits and looks very much like a condensed used light oil. It doesn't look good on the floor later after it has dried and it is slippery.
Try to catch some in a wide open container, then wait a day or two to see if it evaporates away in a warm room. If it does then its just water vapour with some captured muck and is perfectly normal. After a few days Oil will still be Oil. Water will have vanished.
Once the whole system is up to full temperature all the metal will be hot and the fumes will stop condensing. Then the drips will stop and it won't be an issue.
Cans without a drain hole are designed around the assumption that all trips will be long enough for the whole system to always heat up to a point where this will happen. Once it is all hot enough the initial condensation, now in bottom of the can will evaporate away. Living in the UK, and sometimes riding in winter, I disagree with that assumption.
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