none resistor plug caps

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steve c
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Fri Nov 07, 2014 3:08 pm

For the decade I have been using 5 kilo ohm resistor plug caps from ngk, tried several new ones on a Lambretta 200cc and it has always been a problem to start from cold ok after its run, the spark is only visible at the end of the stroke its 19 degrees before top dead and I have strobe light checked it, standard 20mm , clover leaf exhaust, Indian electronic and cdi, I have had this issue with other 200cc and 175cc with Indian electronic kits. There is no way financially I can go over to a certain expensive German /Chinese made alternatives as my scooting is on a tight budget.
Fitted a none resistor plug cap and I can see and hear the spark the bike starts second kick cold! Has anyone else experienced low output cdi units or had any experience with using none resistor plug caps on Lambretta long term ?

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dapper
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Fri Nov 07, 2014 3:33 pm

I've given up with NGK after having a bad batch and several others had same problem too. Only use Nippon Denso or Champion plugs now. The ND numbers equate to 3 X the NGK number, ie. a ND 21ESU = NGK B7ES, ND 24ESU =NGK 8ES, available from MB or on E bay.
Compact Toolbox Flywheel Holder

steve c
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Fri Nov 07, 2014 3:56 pm

there were some fake ngk plugs about and ngk plug caps ( I had one these it fell bits fitting it).
I have got champion n4c ( c is for copper) I will give that ago.
good quality silicon 7mm ht lead seems to suit Indian cdi's better, I have got a Ducati one but I can't remember which scoot/ box its in,
but changing the cap has made all the difference but not the neighbours tv set I would suggest.
The spark is now blue it has obviously improved, Using the 5 kilo ohm resistor plug caps from ngk starting was very borderline (I could hardly see a spark)and got better as the engine fired. Thanks to the deluge of rain I haven't tested it on the road yet and I would expect it to run better.

goldeneye
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Fri Nov 07, 2014 5:52 pm

Nippon denso iridium plugs and NGK red rubber caps on all mine.

Revit
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Fri Nov 07, 2014 6:04 pm

Non suppressed is defo the way to go in any flywheel mag or Lucas type etc. Brightspark have a short tech article on it with a simple data chart -
http://www.brightsparkmagnetos.com/faqs ... gnetos.htm

Spot a fake NGK -
http://www.ngk-sparkplugs.jp/english/techinfo/fake/

Muppet
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Fri Nov 07, 2014 8:12 pm

Revit wrote: Brightspark have a short tech article on it with a simple data chart -
http://www.brightsparkmagnetos.com/faqs ... gnetos.htm
did i read rite :? brite spark tech article showin results for dc ign spark; our ancient scoots are all ac spark im thinkin
C’est la vie

Revit
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Sat Nov 08, 2014 12:25 am

I agree it is rather confusing, what they're talking about is the 'underlying DC component of the HT voltage immediately after the spark is struck. Have to admit I don't fully understand that part myself, but what I can tell you is that all magnetos work on the same principle - either a magnet rotating round a fixed coil (as we have in our Lambys) or a coil rotating around a fixed magnet as most vintage Lucas, BTH etc

Fudgy
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Sun Jul 08, 2018 10:40 am

Just bumping this up as I am also having the same problem cold starting my indian gp with a 5k cap as the one that was originally on started falling off.
The running definitely feels different.
I have just ordered an NGK plug cap without a resistor.

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