Author Topic: Oil being forced from breather  (Read 571 times)

Offline bikerboy

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Re: Oil being forced from breather
« Reply #30 on: 09.06. 2024 18:09 »
I'm still really confused must of the advice points to poor scavenging and poor return resulting in excess oil in the crank cases. My return is very strong seems almost too much it really is returning under pressure it is leaving the return pipe and hitting the opposite side of the tank under pressure
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Trust me I was the maker of the thread confused, baffled and covered in oil and my return was excellent to the tank but I still had the same problem. I have not read all the comments but from what I have read it might be the ball in the scavenge pipe sticking. I think the mag  change is a red herring its more likely that it stood for a while that has caused it.


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Online berger

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Re: Oil being forced from breather
« Reply #31 on: 09.06. 2024 20:39 »
is the return in the tank going at a full 1/8th inch diameter flow and hitting the back of the tank or a thin jet like there is a restriction 

Offline Andy Williams

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Re: Oil being forced from breather
« Reply #32 on: 10.06. 2024 16:20 »
hi again many thanks,  the return to the tank is the full flow and still hitting the other side of the tank, i cant work out where that much oil is coming from assuming the return has twice the capacity as the feed ?
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Online muskrat

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Re: Oil being forced from breather
« Reply #33 on: 10.06. 2024 20:54 »
G'day Andy.
Just wondering. Is that the original oil tank? If so has the return stand pipe been altered? Could the hole be smaller than original?
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Re: Oil being forced from breather
« Reply #34 on: 11.06. 2024 02:06 »
hi again many thanks,  the return to the tank is the full flow and still hitting the other side of the tank, i cant work out where that much oil is coming from assuming the return has twice the capacity as the feed ?

From memory the width of the return gears is only 30% bigger than the feed.
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Online limeyrob

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Re: Oil being forced from breather
« Reply #35 on: 11.06. 2024 08:04 »
That sounds about right, I rebuilt my pump recently (lapped the joints faces) and while there is a size difference its not massive.  The return oil is aerated (and a bit hotter).  Since fitting an return filter I've noticed it makes the return flow more continuous.
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Online Colsbeeza

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Re: Oil being forced from breather
« Reply #36 on: 11.06. 2024 12:07 »
At 5000 engine rpm, Supply side = 1.20 lpm, Scavenge side = 1.67 lpm.
Can show more details if needed.
Col
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