3 replies to this topic

[Edington]

Firstly I searched the forum and found some very useful info on coils posted in 2010 and thought I'd cracked it, but no! As far as I believe every thing to be original as I bought it back in 2001 from a lady who bought it new. The only change I've done over the years is to fit a stage one kit. Unfortunately my son laid it up outside since 2007 and from 2023 I've been trying to bring it back to life. 

 

The Sky has an electronic Dizzy 65DM4 and the coil is a BOSCH with the following data stamped on the base 0 221 118 363 underneath 847 965 also KW 12V

 

The two wires from the dizzy, one black and one red go either side of the coil - and + 

 

I'm hoping that during the engine out restoration that it has all gone back as it should, but I am getting forgetful in my old age

 

 

 

[Ethel]

The wiring sounds correct red to coil + , black to -ve & also a white to the +ve terminal (12v ignition live)

 

Can't find anything on the coil but if you can measure the resistance between those +ve & -ve terminals ( no wiring connected) it should be around 1 ohm. If it's 3 ohms, it's the wrong coil. If it's 1.5 ohms it's intended for ballasted ignition & there's been some debate if that's suitable, but the factory original was 0.9 ohms by its specification.

[Edington]

Thank you for the feedback. I've looked more closely at the wiring and connected to the coil + is a pink wire with 'RESISTIVE' printed on the sheath. There is a white/yellow wire also on the coil +, in addition to the Black and red wires from the dizzy. Unfortunately I can't measure the resistance due to its very low figure. I'm wondering whether to replace the coil with a suitable one from Mini Spares. If so what type? 

[68+86auto]

You need to measure the resistance of the coil. it must be around 0.8 or 0.9ohm. Using any coil with higher resistance will kill the coil over time.

 

Then you need to measure the voltage supplied to the coil but only on a running engine. Testing without the coil being switched on will give a false reading but you could connect the coil negative to ground for testing with the engine off. this must be around the same as the battery voltage. It sounds like you haven't bypassed the resistor so the coil and distributor supply will be too low.

Edited by 68+86auto, 11 October 2026 - 10:42 PM.