A post-script to the oil filter kit saga.
My recent new membership of the Yahoo Bonneville Owners Club message board has made me aware of a T140 oil filter kit that addresses my concerns with either the TT kit I first tried, or with the "Pilgrim Special" I am now running. This kit (priced at US$179.95, with free Triumph lunchbox!), and fitting instructions that demonstrate its design principles, can be seen here.
The main thing to note is that it's a spin-on oil filter that sits inside the frame's oil chamber, mounted onto a replacement sump plate in a way similar to the Pilgrim Special, but it is a pressure-side filter (i.e. supplied by the return-pump of the engine).
Oil travels from the return oil-pump under pressure to the filter, and then from the filter back up to the frame oil-return hosetail by the seat nose. There is a third hosetail on the kit's alloy casting that sends oil to the engine's delivery-side oil-pump in the usual (and unrestricted) way.
So ... you get the best of both worlds with this kit.
It's a pressure- side filter, so there'll be less concerns about clogged filters starving the oil delivery pump with potentially catastrophic consequences.
Yet it fits into a space inside the frame where the filter won't get in the way of other things. Like servicing the rear brake hypdraulics.
If it also results in no hoses being kinked at 90-degree angles (as on the TT kit I tried earlier) then it should be perfect for the job.
