Magnetic timing pickup - kart

[Blue_SV650S]

Right, I have put this up on a karting forum, but just on the off chance someone here might be in the know:-

My magnetic pickup for may Alfarno Pro kart laptimer clicky started to only work intermittently, long story short, I took it apart to find out what was inside to see if I could fix.

Clearly they are a sealed unit and it indeed ended in tears going at it with a hacksaw and a Stanley knife!!

Anyway, before going in there, I presumed it was simply a little reed-switch doing the hard work, Mr Hacksaw confirmed this (as he smashed his way through the reed switches glass!!).

So ...

A new pickup is ~£60, but you can get reed switches from places like Maplin for a coupla quid e.g. clicky (always gonna pain me to spend £60 on a part I can probably make myself for <£3 and <20 mins work).

Now I am happy to have a bash at making my own (was going to wire up, place in old surround and fill with silicone sealant), but clearly I really need to know the spec of the alfarno reed switch. Not only from a sensitivity point of view, but are they heavy duty ones/automotive specific ones to put up with the vibration (no point if it falsely switches through vibes!!).

Anyway, any help on specs would be appreciated!!
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