High speed swing arm oil filler

It has the spin on filter in the normal position. I was going to fill through the centre 1/4" UNF bolt hole however as part of my new bush and spindle job I put a pair of ring clamps on the swing arm tube and drilled them for grub screws to improve the pin location. Collectively they are putting a slight load on the swing arm pin since if I try to remove the 1/4" UNF bolt which was finger tight on insertion it now needs a spanner so I am loathe to remove it in case the pin spins slightly and I can't get the bolt back in again. 

Part of the problem is the replacement swing arm pin which, although it is threaded both ends to ease removal, it lacks the generous countersink the old one had. The tube in the photo is off a WD40 can and I had to relieve a portion of the circumference of the hole through the centre of the pin with a Dremmel to get that in. The oil is thick and at present temperatures even using the syringe I can't develop enough pressure to increase the flow rate very much. 

No it is in the dirty box ahead of oil tank removal. Needs some work to determine if the leak is from the banjo washers or if there is more than one leak.

But, since the filter isn't fitted at present, have you a cunning plan to share?