Anti drain valve? can I use it in the breather?

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Jan 21, 2008
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Anti drain valve? can I use it in the breather?

I was given a new anti drain valve by a friend who did not want to trust fitting it to his bike. I am still waiting on my Dorman brake valve from America so I was wondering as its a ball bearing & a spring will it work in the breather pipe to the oil tank? My breather appears to be pumping as much oil as the return pipe. I have now altered the tank cap & run the breather into the oil tank. I have also filled the tank with 3 pints!!
Hope to run it up at Lydden & see if it helps. hopefully stops its antisocial behaviour.
all the best chris
The anti drain will be too strong and will retain too much pressure, the best valve in the breather is a reed valve which will open with very little pressure and keep up with the engine speed.
If you take the spring out fit it upright it'll work fine providing the bore is big enough. I ran a Guzzi springless ball valve for years. However I've fitted a Yamaha 650 reed type valve early this year, I can't tell any real difference , perhaps the motor can and it looks better, nice alloy etc.


Thanks for the advice.
I will wip the spring out & try that for now.
Hopefully I can sort something out before Snetterton next weekend.
all the best Chris
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