Engine breather pipe

I am trying to install a genuine Yamaha lighting kit to my 2001 WR400f.

Unfortunately there were no instructions.

There is this shaped rubber hose in the kit and I think this is an engine breather pipe. If I fit this pipe what will happen to my jetting because at tick over there is air coming out of the standard breather pipe. The engine will be sucking in air somewhere for it to do this?

Hmmm a lighting kit and breather hose ?? Just what kit did you buy !!

Breather hose: some people reroute this so the end is above whatever water-line you may happen to stall in. On start-up this breather hole SUCKS air, once going it blows air slightly along with a light foam of engine oil. So if you stall and try to start with this breather underwater you suck in loads of water + whatever is suspended in the water...not a good idea. As far as 'installing' goes..you already have one so the only reason to re-install would be to find some solution to the water suck thing: some people simply reroute with the end higher, endlocatioons vary from under the seat to in the air box to under the handle bars. Some also put a T junction in to do the same but leave the original pipe routed to the same place: this allows the oily foam to drain whilst also leaving the opportunity to 'breathe' from a higher point should you get stranded in water.

Now about that lighting thing...just route all your cable through the breather tube and everything should work!


PS Me mums from Preston and I almost married a Chorley girl ...but didnt...long story !

:) Read somewhere on here before that the UK genuine Yam kit, includes the alternative breather pipe, which routes along the frame to the spiggott on top of the airbox boot (you'll have to drill it out first!) This has the main advantage of no water/dust ingress as it is past tha filter side of things, and oil/spather that gets pumped out is re-cycled by the engine. Altogether a MUCH better idea than lettin it Dangle in whatever it wants! :D

Also it should have NO effect on your jetting what so ever as the air you feel is from the engine internals whirring round and instaed of venting to atmosphere you are putting it straight back into the motor!

[ January 21, 2002: Message edited by: Guy ]

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