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Question about rerouting breather line to air

5155 Views 11 Replies 6 Participants Last post by  Brand'd
I have a 98 evo head breather motor. To get rid of drippy air filter, I lengthened the outlet hose and ran under frame to the atmosphere.
I was wondering, since originally the hose vented inside air filtered area to carb, it was adding some air to the air/fuel mixture slightly? If you put your hand over the hose when engine is running, you do feel air pushing (and of course oil mist).
I wonder if it affects maybe the air/fuel mixture at idle or so?
I have noticed a little difference on cool damp morning lately.
It's a mikuni hsr42 out of the box for an evo (stage one style headwork and a ev27 cam)
I'm no official mechanic, I'm interested in others opinions
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I would suggest if you're getting significant oil "mist", as you call it, coming from your hose you may want to look at replacing the umbrella valves in the rocker boxes. They dry out with age. A good running motor doesn't blow much oil at all.
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If you lengthen the breather line a bit and make a trap in it you'll minimize the oil spray.
This is a common "bandaid" fix. You're not fixing the problem, you're just covering it up. It's like thinking you've solved the problem of oil dripping onto your driveway by placing a pan under your leaky vehicle. Sure, you've stopped it from making a mess, but it still leaks.
Well, technically, the pan under the vehicle would solve the problem of oil dripping on the driveway. Jus sayin
Yeppir and that's what I'm saying. They see the result of the issue. Not the issue.
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