Model 31 Oil Problem

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John Grew
Posts: 39
Joined: Sat Dec 03, 2011 6:35 pm
Location: SUSSEX UK
Location: SUSSEX, UK

Re: Model 31 Oil Problem

Post by John Grew »

Sorry if this is in the wrong box , but I always struggle to find my way around this forum. Any way AJS M 30 1957. Completely rebuilt engine.Leaked oil from the start from places that it shouldn`t. Concluded that it was not breathing properly so I added a small breather from the front N/S ex rocker box. Reduced the leaks but now blew oil out of the breather pipe. Increased pipe size and changed oil to 50. Still pumps out of the pipe. Any clues as to what I have done/not done?
John Grew
petert120r
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Joined: Fri Jan 03, 2003 12:00 am
Location: POWYS UK

Re: Model 31 Oil Problem

Post by petert120r »

Check the flap valve inside the large crankshaft nut securing the primary sprocket. Should be free when you blow from the crank end.
JimFitz
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Joined: Thu Feb 27, 2014 9:27 am
Location: Kent, England

Re: Model 31 Oil Problem

Post by JimFitz »

petert120r wrote:Check the flap valve inside the large crankshaft nut securing the primary sprocket. Should be free when you blow from the crank end.
Echo that. Mine was leaking everywhere and the flap valve was gummed shut. Took it off and soaked it in petrol for a day in a jar then cleaned it thoroughly with carb cleaner spray. Also worth cleaning out the crankshaft drilling with some spray and a piece of wire and an airline.
With it all back together with the bike on tickover it is possible to feel the air puffing out on the back of your hand.

Jim
Too old to Rock and Roll but too young to die.

1952 G80 rigid, 1960 G12 DL / Watsonian Monza, 1954 G80S.
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1608
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Location: ESSEX UK

Re: Model 31 Oil Problem

Post by 1608 »

From where is it leaking oil?
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