GRITTY PROBLEM
Chris Allen says: “I have a late BSA A65 frame that’s been grit blasted at some time; I’ve got the worst of it out of the oil-in-frame chamber, but do you have any good ideas for removing the rest?”
This is a common problem – people forget that blasters may be more familiar with iron railings than lubrication systems of old motorcycles; it’s your job to ensure sensitive areas are masked off securely. With oil-in-frame, there is no ‘sump’ as you find in an oil tank; the outlet is at the lowest point, so any nasty debris that can bypass the gauze filter will get into the engine.
I’d steam clean (hot pressure wash) the chamber – the combination of heat, power flushing and detergent should shift any lurking abrasives. I’d also fit a sump-plate oil filter kit. Sold by Shropshire Classics (01743 860146) and others for around £60, these came originally from Charlies in Bristol. I fitted one to my T140 back then; simple and unobtrusive, I was very happy with it, although they’ve been criticised more recently (mostly on internet forums) for being on the feed side, where a blocked element would cut the oil supply, with their recommended alternative being a car-type canister filter in the return.
But given that the feed has the weight of the oil reservoir behind it, a filter should be no problem unless blocked – and assuming you don’t put a lucky handful of grit in with every oil change, why should that happen anyway? With my Bonneville, changing the oil every 1000 miles and the filter every 3000, I experienced no pressure problems. Whether Chris decides to keep it on there after the first few oil changes is up to him, but I think it’s worth it for now.