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View Full Version : Heavy smoke coming from breather hose



wilber1191
04-30-2012, 5:03 PM
I have heavy smoke coming from my head breather hose. I have 16000 miles on a 96 sportster. I last changed the umbrella valves about 5 years ago but have not put many miles on it.

It was not smoking before it was parked for the winter.

Does it sound like a simple fix of new umbrella valves or could it be a simptom of something more serious.

Motocrash
04-30-2012, 5:25 PM
Sounds like a ring job is in order.

wilber1191
04-30-2012, 6:45 PM
Smoking from breather not pipes

ARBY
04-30-2012, 7:50 PM
Right. If it was from the pipes it would be a valve job.

tobiism
04-30-2012, 8:06 PM
Bad rings will DEFINITELY put a shit ton of smoke out of your breathers. Just had it happen to me. The blowby will find an exit somewhere and out the breather it will go!

wilber1191
04-30-2012, 9:55 PM
Forgive me but would not there be blue smoke from exhaust pipes with worn rings and why would it start so suddenly without warning. It did not start slowly. :confused:

hawtpocket
04-30-2012, 10:43 PM
Forgive me but would not there be blue smoke from exhaust pipes with worn rings and why would it start so suddenly without warning. It did not start slowly. :confused:

Blow by is when you have bad piston rings. Some of the combustion gases and/or fuel is allowed to escape past the rings into your crankcase which breaths through the heads on your particular bike.

What arby was alluding, to was a bad valve guide seal or possibly some other valve related condition. In that case, oil would be allowed into the combustion chamber from the rocker boxes which would result in the burning of the oil, producing a blue smoke in the exhaust. This condition can also be identified by especially dark, sooty plugs and in some cases a sooty residue in the intake manifold.

Motocrash
04-30-2012, 11:08 PM
Aye.
When I know I'm not going to ride one of my bikes for several months, I pour a little oil in the cylinders. It keeps the rings from rusting/gumming to the cylinder wall or the ring grooves. Nikasil cylinders are less prone, cast cylinders and cast rings can rust up in a relatively short amount of time. It doesn't take much rust to push a border-line ring job over the edge. Not a huge or overly expensive job. Look at it as a chance to climb around inside your motor and have a peek.
:cheersmate:

wilber1191
04-30-2012, 11:19 PM
Blow by is when you have bad piston rings. Some of the combustion gases and/or fuel is allowed to escape past the rings into your crankcase which breaths through the heads on your particular bike.

Now I get it thanks for all the quick relies. Have thunderstorm heads and piston in a box with cams. guess I will need to put them in now. :clap for you: