Author Topic: Primary Chain Case Leak Plunger A10  (Read 1242 times)

Offline Stu55Flash

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Primary Chain Case Leak Plunger A10
« on: 19.11. 2010 13:49 »
I can't get rid of my primary case oil leak. Had 3 goes so far. Chain case cover is now OK, had the clutch off and replaced the lip seal. Oil thrower is in place. Still oil comes down the back of the chain case like its coming from the shaft. The gearbox output shaft looked well centered.  Other than getting an expensive belt kit has anyone experienced this or got any suggestions? What about grease on the primary chain instead of oil?

Any advice gratefully recieved.

Stu
"Keep a distance from lady "L" drivers in cars. Some are not mechanically minded, are slow to acquire road sense, an are apt to panic..." The Pitman Book of the BSA Twins.
Golden Flash Plunger 1955, Francis Barnett Falcon 67 1954, Ferguson TEA Tractor 1951. Looking for another project!

Online bsa-bill

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Re: Primary Chain Case Leak Plunger A10
« Reply #1 on: 19.11. 2010 15:05 »
Grease is a very poor lubricant on a chain and an even worse coolant.
My friend was advised to do this and tried it on a short run, result red hot chain.
Primary chain travels at a good rate of knots and needs the cooling effect of a dip in the oil as it goes around, doesn't take much but none is not good.

I'm only familiar with S/A Flash so you've lost me with the lip seal, but others will know what you mean so next reply might be more helpful
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline chaterlea25

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Re: Primary Chain Case Leak Plunger A10
« Reply #2 on: 19.11. 2010 15:32 »
Hi Stu,
I'm not over familiar with the plunger version either!, but!!!
Is the oil coming from the gearbox out along the sleeve gear bushing or / and out from the bearing along the splines to the sprocket nut?? or even the gearbox sprocket seal??
The gearbox quite often leaks out the shaft if the bike is left on the propstand *sad2*

HTH
John O R
1961 Super Rocket
1963 RGS (ongoing)

Offline Stu55Flash

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Re: Primary Chain Case Leak Plunger A10
« Reply #3 on: 19.11. 2010 17:46 »
On re-looking at the BSA service sheets, at the very end of Sheet No 208 last paragraph, it says that the screw marked red should be moved to the hole next to the adjuster screw and the chain case modified on the inside to act as an oil level indicator.   I've done this now. It says elsewhere to put 1/2 pint in the chain case but after removing the re-located screw 1/4 pint pours straight back out. Leaving 1/4 pint in the chain case. It this enough oil? Has anyone else done this?

Stu
"Keep a distance from lady "L" drivers in cars. Some are not mechanically minded, are slow to acquire road sense, an are apt to panic..." The Pitman Book of the BSA Twins.
Golden Flash Plunger 1955, Francis Barnett Falcon 67 1954, Ferguson TEA Tractor 1951. Looking for another project!

Offline A10Boy

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Re: Primary Chain Case Leak Plunger A10
« Reply #4 on: 19.11. 2010 17:53 »
Its enough if its still "wetting" the chain. But beware, a dry chain will fry in about 1 minute.
Regards

Andy

1960 A10 - Black Golden Flash
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Online bsa-bill

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Re: Primary Chain Case Leak Plunger A10
« Reply #5 on: 19.11. 2010 18:49 »
Plunger primary case capacity is given as 100cc which is less than a quarter of a pint (568cc = 1 UK Pint) so your ok at that
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline Stu55Flash

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Re: Primary Chain Case Leak Plunger A10
« Reply #6 on: 19.11. 2010 23:42 »
Spot on thanks folks.

Stu
"Keep a distance from lady "L" drivers in cars. Some are not mechanically minded, are slow to acquire road sense, an are apt to panic..." The Pitman Book of the BSA Twins.
Golden Flash Plunger 1955, Francis Barnett Falcon 67 1954, Ferguson TEA Tractor 1951. Looking for another project!