classic motorcycle forum
Motorcycle Discussions => British Bikes => Topic started by: wallys on March 09, 2020, 11:01:33 PM
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After sitting untouched on its center stand for 6 months my 51 plunger transferred 50% of the engine oil from the oil tank to the primary chain case.
Any ideas why?
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Simple really ,oil flows downhill.....leaks from tank into engine ,from engine into primary.....You re pretty lucky its not all over the floor.......My brother came back from holidays to find oil running out under his garage door,and down the driveway,from bikes that had "never leaked before"......Nortons leak down like this in a week,and sometimes fill the engine overnight.......By the way ,drain the engine before starting ,if you decide to start and pump the oil back ,the exhaust will be flooded ,and smoke for 100 miles.
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Thanks John.k,
I pulled the oil pressure relief valve, the ball has slight rust. I guess that's the culprit.
I can't think of any other way the oil could transfer. I've owned the bike for 60+ years & until now it's been quite dry.
Cheers,
Wally
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Maybe, but more likely crap on the ball's seating or a weak spring.
If you've only experienced oil drain down once in 60 years you've been very lucky!
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Thanks Rex,
I've ordered a new spring & ball.
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The problem may be the oil itself ....oil is ever thinner and more watery.....one upon a time oil was sticky on your fingers ,and very thick when cold .....now even 40 grade is watery.....Dont use any snazzy car oil ...I always use a diesel oil ,and do beware of modern "friction modified "car oils that will make the clutch slip ,if they get into the primary.
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Thanks john.k,
I'm using Penrite 20-50 "suitable for wet clutches" & have done for a while. I'll fit the new spring & ball, fill her up & watch the main bearing for leaks.
Wally
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Gently tap the old ball into the seat with a drift before fitting the new ball.