Forum

[Paul Cobbler]

The spark on my 500 Classic Deluxe (2000) has gone AWOL. I suspect it may be the ignition coil but before I order one from our good hosts I want to test it. Does anyone know what the primary and secondary resistances should be? It is the standard Lucas MA12 4516A coil. Cheers.

[Alan R]

Hi PAUL------- no need to get too "Technical" with a coil...Assuming you've checked all the other possibilities eg HT plug cap, lead, coil connector, HT supply verified, fuse etc, and with all leads disconnected at the coil, place a jumper wire from the battery POS terminal( assuming it's a NEG earth) direct to the POS terminal on the coil... Identify the wire coming from the distributor ie}--- the points (usually a Black with White stripe)and connect that to the NEG terminal of the coil.......... You now have a "Stand-alone" circuit that will fire the plug if all's well.....with the plug EARTHED, and the points closed, flick the points open and you should get a bright, blue spark and a healthy "crack" sound....NO SPARK at all = coil u/s------- a dull red spark = capacitor u/s...... Bearing in mind that the coil and capacitor were both new at the same time (ie at the factory)then it's a good idea to fit a new capacitor as well....... Personally I have had a "LUCAS" coil fail on me last year, as did a Bullet 65 owning friend as well....I spent the extra and fitted a PVL unit..

[Gwilly]

Hi Paul, Resistance readings on standard coil would be in the region of 3ohms primary circuit and 9-10 Kohms secondary..

You could also heat the coil gently with a hair dryer and check any differential with temp rise...

Advise follow Alans advice and you should have it nailed in minutes.. gwilly

[Paul Cobbler]

Alan R and Gwilly - replaced plug cap and tested the coil as suggested - good spark / resounding crack from the points. Put her back together and she fired up first kick. Good to hear here running again, now just need to get her MOT'd and we will be back on the road again before too much more of the summer passes! Many thanks for your help guys - I now know a little bit more about my Royal Enfields and its foibles!
Paul Cobbler

[Paul Cobbler]

I guess I 'spoke' too soon. Put my Royal Enfield back together and seem to be back to square 1, almost! There is an intermittent spark (more orange than bright blue). Have tested the coil and it checks out alright so think it may be the capacitor as suggested by Alan R - I can get an initial spark OK but not much with subsequent engine turn over? My interpretation of this is that the capacitor is not recharging effectively to give consistent sparking. Will it be worth replacing the capacitor as a matter of course, is difficult to fit, what is the cost? I would welcome any further advice on this perplexing issue!Cheers, Paul C.

[PeteF]

Capacitor is only a few quid and easy to fit. Change the points too, as if the capacitor is on it's way out it will probably have caused burning of the points.

[Alan R]

Hi guys----- PAUL COBBLER, agree entirely with PETE F........ Incidentally you should NOT be getting a resounding "CRACK" from the points but at the spark plug.... That scenario confirms my earlier suggestion that the capacitor is indeed U/S and should be replaced along with a new set of points as well...........In another thread elsewhere I also recommend carrying a built-up distributor backplate for quick changing should the road-side occasion arise..... You might find this useful}------ http://www.youtube.com/watch?v=W94iksaQwUo -----------------

[Paul Cobbler]

Hello again Guys, This might (I am sure it does) sound daft - but where is the capacitor situated - there does not seem to be any note of it on the wiring diagram on the workshop manual?! Paul Cobbler

[jaffa90]

Capacitor,condenser,same thing (stores electric),it`s a little cylinder shape thing next to the points (contact breaker points really).