Triumphrat

Barnum

I was checking the air filter and wanted also to clean the tube hanging from its housing when I discovered a film of oil on the bottom of the air box (the filter housing is the air box, right?). The oil was clear and smelled like motor oil. I checked the different tubes in front of the housing : everything seemed normal (and anyway, is there any oil passing through them?). Prior to that checking I was bleeding my rear brake, using a broom to push the pedal from the opposite side, but I did a clean job of it and I can't imagine it has something to do with the oil in the filter housing. Prior also to the filter checking, I did squeeze the the drain tube to feel for any residue. There was some and that squeezing must have pushed the oil in the housing because when I squeezed again there was some oil flooding on the bottom of the housing. In short : that drain tube was full of oil!

And the question that nags me since then : where does it come from?

And that one sounds stupid to me but I must ask : is it normal, is that tube supposed to filled with oil? (the Haynes manual don't mention any oil).

And the existential one : what is the purpose of that tube?

Anyway, I cleaned the oil with a rag, did a "reverse milking" with the drain tube to wipe more oil. (I couldn't remove the tube : I opened the clip with too short pliers but the tube seemed stuck there and I foresaw the difficult task of putting it back in place - I do the little maintenance I can at my sister's garage and I don't always have all the tools I need).

Well, thanks for reading. I'm anxious to read your responses.

2004 T100

__________________
Richard

2004 b/w T100.

Pokeyjoe

The crankcase breather feeds into the airbox. Its the large rubber hose that runs from the base of the cylinders to the airbox along the top of the engine case. Oil in the airbox is normal.

__________________
*
John

Some people are like Slinkies. They're really good for nothing. But they still bring a smile to your face when you push them down a flight of stairs.

rodburner

Its all normal.The oil is just blowby from the engine.There is a black hose running from the crankcase just below the left carb,going into the airbox.Wipe out the airbox,drain the little tube now and then and ride.

__________________
" A man is only as old as the women he feels" G Marx

Barnum

Mystery solved! Many thanks, John and rodburner!

__________________
Richard

2004 b/w T100.

amanger

As the crank and gears turn they froth up and heat the oil causing some of it to turn into a gas.The two pistons rising and falling act like a large pump.The job of the crank case breather is to let this gas escape which would otherwise cause seals and gaskets to leak.
In the past, before enviromental issues, this gas would have been vented onto the road but to save the whales it is now vented to the airbox to be mixed with fresh air and reburnt.
The oil in the airbox is from this gas.Try not to overfill your oil level and you may reduce the amount of oil in the air box. Or buy a crank case breather filter and fit it to the breather pipe then plug the hole in the airbox.

__________________
07 865 Silver Bonnie....Bobbed Guards, Tacho, Grab Rail, Lucas Tail light, Mini Blinkers, Dart Screen, LSL Sport Bars, 1" Longer Hagons, 10mm Raised Forks, K&N Pods, Staintunes, 140/40 3 1/2 turns + 1 shim......etc....etc...

rodburner

A crankcase breather/filter will just put the oil all over the top,back of your engine.I`d leave it as is if you can.

__________________
" A man is only as old as the women he feels" G Marx

CAPTDON

If its not oozing down the side of the engine cases- I wouldnt worry. Its normal to have a little in there. As said - dont over fill the engine & it should be minimal. Just wipe out the mist & forget it. Not a biggy!! Just think it could be like a 60's Triumph & oil oil everywhere!!
Ride & enjoy!! 4 yrs & I havent looked in the box . If it works- dont fix it!! Will have to go in soon. Due an air filter soon! Stil runs like a swiss watch!!

__________________
CAPT D

Kirkus51

+1 for pokey & rod. I bought a crankcase filter at Newbonnie, but haven't decided to put it on yet. I just think they look kewl.

amanger

The purpose of the crankcase breather filter is to allow the gases to escape and trap the oil residue.If you have large amounts of oil venting over the rear of your bike with a filter fitted you would have to be spending all your time riding at redline and building up excessive pressure or overfilling your crank with oil.With the crankcase breather hose venting direct to the airbox there is no filter to catch the oil.Due to the firing order of the Bonnie 360 deg. parallel twin the motor has higher crankcase pressure than any other design.

__________________
07 865 Silver Bonnie....Bobbed Guards, Tacho, Grab Rail, Lucas Tail light, Mini Blinkers, Dart Screen, LSL Sport Bars, 1" Longer Hagons, 10mm Raised Forks, K&N Pods, Staintunes, 140/40 3 1/2 turns + 1 shim......etc....etc...

BorgCymru

You could fit one of these catchers





http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=200231158803