Another Rotor question

BarrieC

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Guys,
following on from my recent Rotor, ignition questions, I have a 1980 bike, pick-ups, Stator and TDI unit and combined Rec/Reg all good. but no TDI Rotor
I have 2 options, buy a Rotor from Ricks (comes to quite a bit with Import etc) or fit a magnet as per Gonzo project.

My Rotor is showing 5.5 ohms between rings, Is that a good enough resisitance to proceed? as i know the limit according to Haynes is 5-7 ohms, would 5.5 indicate on its way out?

Thanks

Barrie
 

nj1639

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I'd say fitting a magnet to a points rotor has to be spot on in application. Jim has a schematic for the placement and if you feel up to the task then by all means epoxy away.....can't hurt anything, though a surface mounted magnet as opposed to an embedded into the face one gives me question to longevity of function (What was that clink?). Like Skull sez on 5 ohms, you're good.
 

BarrieC

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I'd say fitting a magnet to a points rotor has to be spot on in application. Jim has a schematic for the placement and if you feel up to the task then by all means epoxy away.....can't hurt anything, though a surface mounted magnet as opposed to an embedded into the face one gives me question to longevity of function (What was that clink?). Like Skull sez on 5 ohms, you're good.
Thanks Guys,
I'm gonna go with trying the magnet (not a lot to lose) The post for fitting the magnet shows where to drill a hole to fit the magnet in, so it should be secure once its epoxy'd in place.

(Must dash our live politics at the minute is better than any soap opera LOL)
 

nj1639

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Some years ago I fitted a magnet to a points rotor using what, in retrospect, must have been a Neolithic calculation as to placement.....lol. It worked but not well. Since then Jim has come along and 21st century improved the placement proceedings. You should be good to go and please let us know how it works.
 

Jim

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The problem with using a used rotor is the age. Even the newest ones are pushing 40 yrs and some are now past 50.
5.5Ω falls right in line with what it's supposed to read.... perfectly normal. Unfortunately, that's not an indicator on how much life's left in it. The typical failure will be because the insulation starts to break down and resistance starts dropping toward zero. It's more pronounced when it's hot and can actually read "normal" when cold.
Given your choices Barrie, I'd go ahead and mod it. If it lasts, great. If not, you can look to get it rewound.
Iirc, @Paul Sutton found a place over your side of the pond that rewinds rotors. He was quiet happy with the results as I recall. Maybe he'll chime in here.
 
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