Oil Leak

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biggles
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Oil Leak

Post by biggles »

I am working on a 48/G3L and oil is leaking in large quantities from the small square cover plate at the rear of the pump. I have tried removing it and ground the plate perfectly flat but as soon as you start the engine oil pumps out. I have never experienced this before and have taken the pump and pin out and they look to be in new condition. Would this perhaps happen if there is excess crankcase pressure? Any thoughts would be most welcome. Thanks John Tinley
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Rob Harknett
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Re: Oil Leak

Post by Rob Harknett »

The plate should seal OK John. I assume the crank case joining surface is OK. Are you using a sealant on both sides of the paper gasket?
The rear plate of course fixed with 4 bolts. ( unlike the front cap, fixed with 4 screws which are only 3/8" long 3BA.)
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ajscomboman
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Re: Oil Leak

Post by ajscomboman »

There's not a lot of pressure there in normal running conditions. If it's pumping out after being resealed then I'd be looking for a blockage somewhere.
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Rob Harknett
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Re: Oil Leak

Post by Rob Harknett »

ajscomboman wrote:There's not a lot of pressure there in normal running conditions. If it's pumping out after being resealed then I'd be looking for a blockage somewhere.
Also Rob, if using multi grade oil, in particular 20/50 expect more oil to leak than SAE 50 would.
SPRIDDLER
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Re: Oil Leak

Post by SPRIDDLER »

Has it ever been o.k. or is the bike new to you and you haven't previously run the engine?
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Mick D
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Re: Oil Leak

Post by Mick D »

ajscomboman wrote:There's not a lot of pressure there in normal running conditions. If it's pumping out after being resealed then I'd be looking for a blockage somewhere.
Ditto to that - Check the crank case for a crack from the pump bore - failing that a strip down is in order, the majority of the pump output is directed straight to the main and big end bearings, it doesn't sound like yours is getting there.

Regards Mick
56G80S
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Re: Oil Leak

Post by 56G80S »

Have to add that didn't have your problem even with one bolt with a very weak thread into the cases.

I'd vote for exploring potential blockage too.

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biggles
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Re: Oil Leak

Post by biggles »

Thank you all for your responses. I have concluded that there must be a blockage somewhere as I sealed the end cover with great care and made sure the surface was flat. Even after doing this there was a very significant amount of oil coming out. I think there must be a blockage somewhere.
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