Hitchcocks Forum

Has anyone used them I assume on all three drain plugs under the bike? The implication seems to be they will seal at hand tight and a 'Nip'. Has anyone found they come undone or loose when riding? There is an excellent article on this forum about wiring the plugs But wondered if you can get away without as I dont want to risk damaging the plugs with the filters as I have not seen replacements for sale anywhere comment appreciated thanks.(Sixty 5 2003)

They do seal with a nip,but still require a torque to stop them vibrating loose, wiring them is worth the peace of mind

Hi , I've had Dowty washers fitted on all the 3 drain plugs plus on the rocker box oil feed pipes for years on my Bullet '65 . I just nip them down , they require much less torque to seal than a copper washer , that's their advantage . They've been used in the aerospace industry for decades , but EVERY threaded device on an aeroplane engine is locked as well in some way , be it wire locking , loctite , tab washers etc , no lay bys in the sky..... I wouldn't hesitate to use them , saves stripping those threads !!!!!

REgards Roy B

Been using & re using them for years. Particularly good for crankcase drain plug if it is necessary to drain the case now & then

Hi Grumps, I recently bought a few Dowty washers and used them on the drain plugs on my 65. All the drain and filler plugs and filter nut had a right old mixture of copper, fibre and steel washers on. I fit one on the tappet cover stud too, with a steel washer between it and the nut, I never used to get a copper one to seal properly. This is because the boss that the stud screws into is not at the same level as the outer face, so the gasket doesn't seal it. I put a washer between the boss and the gasket to build it up to roughly the same level. I suppose a Dowty one would be good there too, provided it isn't thicker than the gap. Ray.

We used to use them at work on HP gas cylinders. They sealed with just a nip with many atmospheres behind them.

Dowty washers are made by the same Dowty that make Hydraulic pumps and equipment. The washers can withstand immense oil pressures without leaking in hydraulic systems. The rubber portion of the washer is thicker than the steel part and forms the seal when it is crushed down to the same thickness as the steel part. The rubber portion being crushed like this also means that any nut or bolt bearing on it will not shake loose, even if only a little more than finger tight. I use them on the rocker oil feed unions, as well as the crankcase oil plugs and strainers, as well as fuel taps and many other similar applications. Regards, Paul.

Thanks Guys I appreciate the advice. Dowty washers it is then!

PS I assume its the 13.5mm sold by our hosts?

Yes, I got mine from them, they state in the catalogue that they are for the drain plugs. I bought 20, but just for the drain plugs. I remember I used them on the rocker feed banjos on my earlier Bullet, though smaller ones, obviously. By the way, Grumps, I was down your way, at B&Q, today, on the guzzi. Should have rung and met up, sorry!