trouble understanding breathing?

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dunk 1
Posts: 215
Joined: 25 Oct 2007 18:16
Location: cumbria

trouble understanding breathing?

Post by dunk 1 »

here is another of those questions deliberately made to make me look stupid- not hard i know. looking through the forum I
hve come across several references to the importance of the breathers in the rocker covers with relation to the distribution of oil.
my bike has the tubes coming out of the rocker cover but no rubber ones attached as shown on the parts blow up how long do these need to be?
my main confusion though is when the rocker cover comes off . the manual says be carefull not to lose the breater springs and indeed they are there but seem at one end to push against a solid part of the cylinder head and at the other to be attached to a circular metal component with a slot in the side - presumably the breather- however since this also appears to be a fixed component what is the function of the spring ?
should the metal breather part be able to move or am I missing something?
thanks - duncan
dunk
jb666
Posts: 188
Joined: 02 Nov 2006 22:20
Location: Ashford, Kent

Post by jb666 »

Duncan,
The breather tubes need to be long enough to allow the water and oil condensate to drip anywhere except on your bike or on your boots! If you look at a review picture they tend to run down the frame tubes and end about an inch (25mm for the youngsters!) below the bottom frame tube.
The spring you refer to is there to keep the labyrinth in place without it rattling (I think).
Oil mist generated by the rotations of the crankcase contents whizzing about condenses on the crows feet in the rocker covers and drips on the rocker shafts. The vents allow any oily water vapour to escape where it drips out like a yellow mayonnaise. It's only a small amount (or should be). This is most noticeable when the bike has stood after a good thrashing!! You also need to give the engine a good workout to generate the oil mist to lubricate the rocker shafts.

Hope this explains things,

John.
3potjohn
Posts: 1362
Joined: 02 Jun 2007 13:58
Location: Devon

Post by 3potjohn »

I found that if the bike has not been run on anything other than short journeys (a bad thing for an engine) there was appreciable mayonnaise in the vent pipes. All reminiscent of when the water pump seals go on a BMWK75. And probably explains rusty left exhaust pipe.
I use a pushbike for short journey thereby avoiding these issues and have filled up the silencers with old gearbox oil from my R60 in a bit to prolong their life and emulate a Kawasaki triple.Or come to that my old T150.
EVguru
Posts: 1530
Joined: 01 Aug 2006 11:13
Location: Luton
Contact:

Post by EVguru »

The breather/oil seperator is conical in shape and so will wedge itself in the rocker cover. You can easily prise it out with a screwdriver for cleaning.
Paul Compton
http://www.morini-mania.co.uk
http://www.youtube.com/user/EVguru
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