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MG Midget and Sprite Technical - No spark

So I'm finally at the point when I'm ready to attempt to start my newly rebuilt '71 1275. Needless to say nothing is happening with the most obvious fault being no spark from the coil. My 1st ever try with a multi-meter read 4.0 or so on the ohm meter when attached to the coil - is that good? I installed a petronix electronic ignition system during the rebuild and think it's all coupled up properly: red & ignition wire to + black to -...

Should I just replace the coil to see if it's the culprit? Or is there another way of checking its health?

When I first tried to fire it up there was smoke from the starter - I cleaned up the earth strap contact and that seemed to take care of that. Could that be contributing?

Any suggestions would be most welcome.

Thanks
Simon

Simon Fryer

Testing the coil is very simple

I simply connect the -ve side of the coil to earth, place a plug lead into the HT connection with a plug attached that is also resting against earth. Then with a wire connected o the +ve of the battery flash this wire on and off the +ve of the coil. Each time you do this the spark plug should spark. Simple!!

I suspect your problem is NOT the oil and I understand you have fitted electronic ignition. Surely that may be the problem no? Is that all connected correctly? perhaps it could be good to go back to points just to make sure everything else is correct.
Robert (Bob) Midget Turbo

Are you sure the smoke was from the starter and not the dizzy, take off the cap and check none of the wires have burnt out, if the electronic ign has been wired wrong this will cause damage to wiring, as bob says go back to points and try that first and worry about electronic ign after, that eliminates at least one thing.
Good luck
Rob Newt

Coil - OK... problem sourced to deficient wiring at Tach. All fixed and good spark at plugs. Suspect timing wildly off though as no firing. That's today's job...

Many thanks Bob & Rob!

Simon Fryer

Simon

When fitting a pertronix unit, you MUST re-set the timing...the trigger point is different from points.

I've been running my 1500 with a Pertronix distributor since last summer & love it!

Let us know how it turns out.
Dave Rhine ('78 1500)

the easiest way i found (came from an old engine guy...not mine) to set static time on a pertronix is remove #1 spark plug, remove coil wire from dissy install the spark plug in the coil wire and ground the spark plug, rotate dissy till spark plug fires, lock down dissy.

you got static time. Done...re hook up, and fire

obviousy you will need a coil to dissy wire that is booted at both ends that can fit the coil at one end and the spark plug at the other end...3 dollars at my local savage yard, or free if you feed the yard dogs and fill there water bowls...I choose the 3 dollar option. I like my fingers as is.

Prop
Prop

Removed the Pertronix and re-installed points just to be safe. Static timed engine and after some churning it burst into life. First time in 10 years! Will try the Pertronix again later.

Thanks everyone.
Simon Fryer

This thread was discussed between 24/07/2010 and 27/07/2010

MG Midget and Sprite Technical index

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