Norman jet continued

Well Maplin let me down - micro drill sets out of stock - so I thought
again. Perhaps I could make a broach out of a pin or something? I raided
Helen's sewing box and found a needle which the digital verineers told me
was 0.69 mm in diameter. looking at it, I thought who am I kidding. I can't
cut teeth on that, anyway it would have to be a pusher rather than puller
and even without resorting to Euler's formula for the buckling of struts
(see, I do remember something from that failed engineering degree - just the
name you understand, not the formula), I could see that was a non starter.
Maybe I could use the needle as a lap - wrong way round I know, a lap is
supposed to be softer than the material to be worked. But anyway I chucked
the jet an mounted the needle in the tailstock, smearing it with polishing
paste. With a spindle speed of 1360 I advanced the needle, occasionally
withdrawing it to redistribute the past, and slowly, but slowly it began to
disappear into the jet. Well something was happening, either I was opening
out the jet or reducing the diameter of the needle! Once the parallel
portion of the needle was well into the jet, I got the verineers out again
and the diameter of the needle was unchanged - success!
Cleaned thoroughly and reassembled into carb - would the T300 now start ok
and run off choke? YES! Put that in your pipe and smoke it Mr £82 carb man
Reply to
Nick H
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There's not the slightest chance it was just bloked then !!!!!!!!!! :-))
Martin P
Nick H wrote:
Reply to
C> There's not the slightest chance it was just bloked then !!!!!!!!!! :- C> ))
C> Martin P
None, it was very thoroughly cleaned and anyway was clearly marked 50, when all the evidence points to needing a 70 (1/100 ths of a mm).
Reply to
Nice one , I can remember doing the opposite on a Russian motor cycle, a Dnieper 350 2 stroke. It was OK flat out but obviously hugely too rich, I rang the importers "Could they supply me with a leaner jet "? They could supply me with hundreds of jets but the numbers bore no relationship to the size of the hole, handy really. I decided to drill and tap the end of the jet cover 2BA and solder the end of a sewing needle into a 2BA screw. Some practice screwing in and out until the needle was in the jet just the right amount , and it ran perfectly. Steve the grease
Reply to
R. L. Driver
"R. L. Driver" wrote (snip):-
Yes, I was pretty chuffed. Thanks to all those on and off group who offered advice and information.
Reply to
Nick H
Proper incentive moving one to the right idea & good planning & proper knowledge of properties led to success! Job well done Nick, nice when it works, innit!
Kim Siddorn
"Nick H" wrote in message
Reply to
Kim Siddorn
"Kim Siddorn" wrote
Either that or necessity being the mother of invention ;-)
Reply to
Nick H

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