1963 650 SS Oil Return Pipes

I understand that 'proper' hose clips - the type including a flat spring steel band right round the pipe and overlapping at the ends - is preferred to Jubilee Clips, because Jubilee Clips in smaller sizes tend to ruck up the pipe below the closure point.

But nothing I own is oil tight anyway.

Hello Gents - Norton's used crimped fittings on those oil pipes.  If you're going down that route make sure you buy the correct ferrules to fit your piping.  Allow enough slack to permit the pipes to flow through the bend required to fit to the bottom of the cases.  There is a little slack at the oil tank fixings if required.  The oil pipe ferrules are usually zinc-plated brass, unlike the ferrules for fuel pipes which are usually nickel plated and thinner gauge. Good luck, Howard   

My 1960 and 61 Dommies came from the factory with no clips at all ,and did not leak , the stretchy pipes gripped the fittings  and with no  significant oil pressure in the pipes  little clamping should be needed. Its only an issue when more rigid pipes are subtituted. Many owners viewed the push on pipes with suspicion and fitted clips anyway !.

Try different hose with a different size bore, the clip is to stop the hose coming off not seal it.