1962 Norton 650SS Crankcase breather / oil tank

texasSlick said:

The spot welds are the weak points. Eventually, (perhaps 30 to 50 K miles) vibration will fracture one or more welds, opening up a leak path from inside to outside the tank. The resulting leak, or weep is easily mistaken for a oil filler cap leak.
I first brazed the tab all around to stop the weep, but I do not recommend anyone to follow suit as this only contributed to the metal fatigue problem and precluded welding afterwards. The proper repair is to cut away the tank roof and replace the roof and tab with a heavier gauge steel.

Hopefully, you will have many miles of service before you have to address this issue.

Slick

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Bodger said:

Not certain if I am understanding the discussion, but the oil tank should sit on a rubber pad and the top bracket should have rubber of some sort between the tank bracket and frame tab. The rubber mounts should allow the tank to move. If it does there should not be any problems with the top bracket fracturing.

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texasSlick said:

Well, mine was mounted exactly as you describe, (factory original) and it did fracture, first the spot welds, then after brazing the tab, the vibration crazed the tank roof into a spidery web of cracks.
I purchased a spare tank from ebay and apparently the PO had the same problem, as he had replaced the tab with a welded on bolt! I consider this a common problem if the bike accumulates enough

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