Hi everyone
amongst all the other small problems I've had and fixed, I noticed that I am without a crankcase breather hose at all. I have read a few posts about this tube, but mine just has a small traingularish shaped hole on the top of the crankcas, and checking against my 86 model spares bike, it had the same, with just a small tube stuck in it a fair way, and looped down and out under the crankcase. (to breath I assume).
Anyway, I was thinking of just sticking this tube in on my 85 Blue Max, but other posts seem to suggest it should have a more formal setup.
Anyone seen anything similar?
Thanks
RT

triangularish hole ? wow rt ....

but yes the breather is important ....check at the plenum that there isnt a largish hole to the atmosphere, i thought the breather was about 10mm inside diameter so you should find a fairly largish metal tube to mount the breather tube to ....same behind the coils ...more or less slightly forward , a verticle port of about 10 mm



this might explain quite a few things about your idle and all the rest of the stuff that might have been affecting performance

crikey ...i think you need either 1 > to make our workshop day on april 14th up at kingaroy or

2> someone ...or many of us ...to arrive at your place for a few days

wouldnt cost a lot ....well let me rephrase that ...wouldnt cost as much as the bmw dealer ...after all we would expect copious amounts of grog .......grin

Have a look at this link to see whether your bike is 'missing' the all-important crankcase vent hose 'tween airbox and cylinder block. It's item number ten. She sure wouldn't idle or run very well at all without it. It is, as Chazza suggested, at the back of the block behind the ignition coils, shaped like a lazy 'S', and is clamped on at both ends - the airbox and the aluminium flange on the block. Perhaps you're just not seeing it...Or you're taking the piss.

http://realoem.com/bmw/showparts.do?model=0503&mospid=51751&btnr=11_4676&hg=11&fg=11

Well obviously I have given you guys a misleading description. I will try and get a piccy later today. It is not the S shaped hose, I replaced that several thousand dollars ago.
When I was away with the boys last year I noticed everyone had two small breather hoses hanging down underneath their bikes. One is the battery breather, and I now guess the other is a "transmission"breather (not crankcase as stated. I have already gone to the back of the class for that).
I actually have neither. The battery I can fix ( except I don't seem to have a nozzle outlet on my battery).
The other is only about 4 mil inside diameter black hose coming form underneath where the battery holding plate sits. When I get my camera out later I can show you. Thanks for your bewilderment.
And no, Guest, was not taking the pess, just being naive yet again.
Cheers
RT

Sounds to me that you have the left overs of a battery breather hose. The small hole under the battery carrier just goes through the case and into the viod behind the swingingarm and was for a battery breather tube. The vent for the gearbox is at the front of the gearbox and almost under the starter (it cant be seen till you remove the starter). If you don't have a little stub to attach a breather to the battery then it is most likely a sealed maintenance free one.
The only breather your crankcase will have is the one with the z shaped tube from the plenum chamber.

So this is normal then, although the tube was vented downwards to the ground.

That is the battery carrier there with tube underneath. Of course my real bike is nowhere near as dirty.

there should be one other tube going down there ...or near there also ...that is the cup under tank drain hose ..

just a heads up

23,11 $ !!!!!!!! the vent hose

any suggestions for somenthing cheaper ????

greecek100rt wrote:any suggestions for somenthing cheaper ????

Buy three of them before the price rises again........they have a short average lifespann.

Placing a order in US?........£10,50 (+VAT, which you don`t pay) from Motobins.

RT: The hose you have in the piccie is an old battery breather hose.

Charlie: The drain hose from the "cup" is routed down behind the right footrest bridge.

Just for info, the early K's, before the 'cup', had two hoses from the tank, vent and overflow, both running behind the right footrest.
Paul.

Thanks,
I can put this one to bed now, something less to worry about.
Now to replace the coolant sight tube, man this is never ending.
RT :arrow: