Crankcase breather cap

[kiroh]

...yes, the one I'm supposed to remove every so often and let some fluid out of the bike... it's GONE!!!

Is this why my sparkplugs are oily and need changing? Shall I plug the hose in with something til I find a replacement?

Cheers

[c stillythemanwivno]

don 't you worry buddy we will keep an eye out for it !

[robelst]

Can't see the link with the spark plugs. The main reason the hose is plugged is because of environmental considerations (many older bikes just let it blow freely).

[kiroh]

Can't see the link with the spark plugs. The main reason the hose is plugged is because of environmental considerations (many older bikes just let it blow freely).

Thanks robelst.

Thought maybe it's sucking in oil and cack from the road and it goes into the engine. Now I can ride without worries.

Cheers

[robelst]

Thought maybe it's sucking in oil and cack from the road and it goes into the engine.

I would not worry about that. I mean, a plugged hose collects fluid and cack and that isn't sucked up either (unless the hose gets all filled up of course )

[stoo]

Can't see the link with the spark plugs. The main reason the hose is plugged is because of environmental considerations (many older bikes just let it blow freely).

It'd be worth stopping stuff getting back in there though...

On my XR, the crankcase breather vents into the airbox.

Most bikes I've seen that don't do that have some sort of filter on the crankcase breather, like one of these....

[robelst]

Can't see the link with the spark plugs. The main reason the hose is plugged is because of environmental considerations (many older bikes just let it blow freely).

It'd be worth stopping stuff getting back in there though...

On my XR, the crankcase breather vents into the airbox.

Most bikes I've seen that don't do that have some sort of filter on the crankcase breather, like one of these....

The hose solution may be primitive but is better than redirecting it back into the airbox. My Buell had a similar setup and suffered from pinking when it was warm: Ever since I use a catch-can that has gone. Actually, I have replaced the end-cap on the AT with a small bottle as well (I am using an old Tesco Multi-vitamin bottle, but I am sure you can buy carbon fiber ones with titanium caps as well ).
Using filters at the end of breathers is completely unnecessary, because it is mostly breathing out. Filters can even get blocked on the inside (!) when not cleaned regularly. It looks interesting though and it might stop birds from nesting

[nellychat]

The crankcase breather cap from my @ is in a jar in my garage somewhere! If your planning some really deep river crossings then it might be worth plugging the pipe, might fill the crank case up!

Otherwise it should be fine.

The @ is the fist bike ive had where the crankcase breather is plugged.

[piguglyshandydrinker]

If it's the cap at the bottom of the breather drain tube, I'd be tempted to put it back, won't the engine draw unfiltered air in???

I could be wrong but if it's the same setup as an Alp, the crankcase is vented to the airbox (engine side of the filter) at a low point of the airbox is the drain tube - complete with bung

Phil

[robelst]

If it's the cap at the bottom of the breather drain tube, I'd be tempted to put it back, won't the engine draw unfiltered air in???

I could be wrong but if it's the same setup as an Alp, the crankcase is vented to the airbox (engine side of the filter) at a low point of the airbox is the drain tube - complete with bung

Phil

The suction through the hose will be virtually zero (there are too many other and much larger openings in the airbox to leave any vacuum for the little thin hose) and it's a long way up to the air-box. Apart from the odd over-curious ant I can't see anything go up and eventually end up in the engine.
If there was really significant suction, the hose would not collect dirt and water but suck that up as well.

I use a little bottle at the end of the hose which I empty every now and then. I dispose it together with old engine oil. I am a very tidy person