Ariel Owners Motorcycle Club

I have inherited a push-pull petrol tap and a gauze filter to fit to it but the filter has no thread in it at the moment to screw the filter into it & so I will have to tap the filter to take the filter
The thread on the filter is 1/4 x 40TPI as best I can measure. Is this 1/4 x 40TPI ME (Model Engineers) thread or something else altogether?

Rod

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Can you show us a picture? Filters are usually soldered into the top of the tap...

The double tap with reserve has a soldered brass mesh filter. Some single taps have the fine 1/4" internal thread. I've sometimes fitter lawn mower nylon filters to them.( Screw in) satisfactorily. Nev

I have seen filters soldered into taps. I think soldering would a tricky business with gauze and such a small fixture and I am not sure how that would have been done originally. I think I would make a mess of it.

I think I have seen instances where the filter was screwed in & could be removed. I'd feel safer trying to tap a thread in the petrol tap recess & that's why I wanted to be sure what the thread was. (The thread on the petrol tap that screws into the petrol tank boss is 1/8 BSP, by the way).

The thread diameter on the brass/copper filter is 1/4" O.D. as best I can measure. The only 1/4" O.D. x 40 TPI thread I can find reference to is M.E. 1/4 x 40TPI.

Thanks for the lawn-mower filter tip, Nev.

I don't know how to up-load a photo, Simon.

Rpger

Roderick.Bradley wrote: ↑Sun Jul 24, 2022 9:22 am I don't know how to up-load a photo...

Forum Help - Posting Images should be of assistance....
viewtopic.php?f=35&t=193

SG

Yes, Les, you're right. 1/4 BSP is the usual petrol tank tap thread size. But for reasons in the past only to be guessed at, it's a 1/8 BSP in this instance. Not the best size.

I think I will go ahead with tapping the other (filter) end of this petrol tap to 1/4 x40 TPI M. E. to be able to screw in the filter.

Rod

All Ariels, except the 2 strokes used, 3/8 BSP, yes 1/4 is more common on the more common sort of motor cycle but not on the better sort. That is the end into the tank, the outlet is usually 1/4 except on the post war Colts when it is push on and the 1954-58 SQ4 when it is 3/16 BSP, which is a bastard thread frequently misnamed 7/16 BSP because it measures 7/16 but as we all know that is not how pipe threads are named!