Valve cover breather

[weaver]

This could be water vapour,you can try catching it in a catch tank to see if it condenses to water.Is the bike using any oil?if not I wouldn't worry about it.

[johnr]

check if its steam and not smoke, if your engine is cold, then the chances are that it will be water vapour caused by hot air coming into contact with cold metal surfaces. you could route the hose to a catch tank or as i used, a guinness can zip tied to the frame, or otherwise you could get one of the lucky 7 catch tanks that replace the sprocket cover. , or you could fix the end of the pipe over one of the cone filters so the vapour is sucked through the motor.

[johnr]

also, as an aside, have you done a compression test just in case your bores are worn. any crankcase ventilation is good, if its an issue, you could route it under the sprocket cover so its blowing its fine oil mist onto your chain.

[fossie]

You will find the tech section once you've logged in. The first 4 strokes from Japan in the 70's routed the breather as John said to the chain to lube chain, this way you won't see it .......so it isn't happening.
If the bike is running well leave well alone the compression readings are with in tolerance.