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XR400 engine venting

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So i am in the middle of a bike rebuild and got to thinking about the engine venting. There is the crankcase vent which dumps out by the airbox. My issue with this is, it sometimes spits oil all over my airbox. There is also a vent that comes off the top of the valve cover and ties into the frame. Now I have two ideas.

1: Since the there is an opening for the timing chain from the bottom end clear to the valve cover, why not run the crankcase vent hose to the frame, this way when the oil gets hot and expands I won't having it coating my airbox and will actually still maintain my oil level. And run a filter off a hose off the valve cover vent.

2: My other thought was to build a small tank that the crankcase vent ties into and then have a filter coming off the tank to solve the oil issue.

Any thoughts

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Number 2 is your best bet. It is called a catch can and can be bought in a lot of places in varying sizes. My Corvette has a huge one since it is supercharged.

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Number 2 is your best bet. It is called a catch can and can be bought in a lot of places in varying sizes. My Corvette has a huge one since it is supercharged.

My thoughts on making was to machine it out of aluminum and have it bolt up to the front tab on the top of the airbox.

Saw your Vette in one of your pics.................looks like a sweet ride

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The Corvette is a spring project but I am working on it now. Putting a 383 stroker in it right now to go with the 2.8L Kenne Bell supercharger. I blew the stock motor awhile ago.

DSC03583.jpg

DSC03575.jpg

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Are you running the end of the vent line "into" the airbox or on the outside of it under the seat? Got a filter on the end of it?

My issue with this is, it sometimes spits oil all over my airbox.

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Are you running the end of the vent line "into" the airbox or on the outside of it under the seat? Got a filter on the end of it?

It's under the seat and dumps right infront of the airbox, no filter. Always seems that when I get into the tight stuff having to use the clutch all the time tends to puke out the oil.

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There's another thread running currently about Ben333 having the same problem. We're down to having him check the screen strainers in the system for blockage. You might try that too.

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Well, I don't think its the strainers, but I will look at them next week when I have it all apart to pull the crank. Never had an issue with it when it was stock. After messing with the engine when I stated having some issues. It's not constant,but it seems to always happen when I am always riding tight stuff and am working the clutch alot.

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I finally got my cases split and noticed one thing, there is only one about 3/8" to 1/2" hole that lead to the area that the crankcase breather. To add to that the gasket that was there was blocking about half of the chamber to the vent tube. I would think that there would be more venting into the chamber from boh sides, not just one side.

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