Misc: Everything Else H.T. Coils

[Bill Thomas]

A bit in MPH July/2018, Paul Adams, Tells us how to check coils, John or Peter Appleton, Sorry not sure, Helped with a faulty Coil, Paul says check with an Ohms meter
across the two terminals !.
I have just checked 5 coils and they all read 100% contact.
We are looking for 2 ish ohms for C.D ign or 4 to 5 ohms for Points type.
By going from one contact to the H.T. outlet I can get 10k Ohms, Maybe my meter is a cheapie ?, I think that is what he meant ?.
I wonder if I can pick, John or Peters brains, Like all "D" owners, I can't find a place to hide the coil, It has been stuck across the left side of the engine, Which I have not liked since 1977 !. I have a 12v Black Plastic coil with 2 H.T. outlets, Which I think I can bolt under the Headstock, Much smaller than the standard one, Can I just leave one H.T. lead off, Or will it Burn out ?. I know you can get small round coils, But I have had trouble with those, Any slight nip in the outer body and they break down.
Many thanks, Bill.

 

[Comet Rider]

Hi Bill,
With a twin outlet HT coil you need both leads to complete the circuit.
These are commonly used on multi cylinder engines with a wasted spark type of ignition system.
Any singe output coil should do what you want

HTH
Neil

PS
On my Comet D type ignition I am using a 5 Ohm single output coil from Dyna

 

[Bill Thomas]

Thank''s Neil, I forgot to say, Testing that coil, I got no reading !, Maybe that's why !.
I was supplied with that one for my Rita,
But did not like it and went back to 2 small 6v coils.
What if I join the 2 leads together, And then into the "D" Distributor ?.
Cheers Bill.

 

[Comet Rider]

Bill,
Nope don't do that....
If you must use that coil, then terminate 1 lead to ground, and the other to the plug/dizzy to complete the circuit.

 

[Bill Thomas]

Thanks Neil, There is always a way !.
Can't see the point of buying more stuff when I have stuff under the bench.
Just tested the twin spark coil and can't get an ohms reading, 100% joining Pos' to Neg', If I join the 2 H.T.s together and to one of the terminal = Nothing.
Or one H.T. to Pos' orNeg' = Nothing.
Might connect to a battery with a Dist' and play on the bench tomorrow, To see if I can get a spark.
I hate electrics, My head is hurting !, Just thought I could put both leads on the plugs.
Then remembered the H.T. lead goes to the Dist' !!,
I have a plug on the other side that once had a decompressor, People are always saying, There is no way that will start with no plug lead on !!.
A bloke said that on Friday, When I was at " Feked" .
I should have just left the coil where it was, But I will Play !.
Cheers Bill.

 

[Normski]

Bill, the reading is across the 2 low tension connections, i.e. not to the plug lead connector. You need a good meter and good meter leads or the result will be meaningless. It's not unusual to get a reading of 2-3 ohms or more when touching the prods together with poor meter leads.

 

[Bill Thomas]

Thanks Norm, All my coils read 100% solid connect, If I join Pos to Neg.
This meter always worked well on Suppressed H.T. leads, When I was in the motor trade.
The fact that it's reading 10k Low tension to H.T. Tells me the meter is doing something ?.
Cheers Bill.

 

[Len Matthews]

A note of caution,if you intend to use a twin lead coil with contact breaker ignition make sure that coil is suitable.Dont use one intended for electronic ignition,that will result in a dead short.

 

[Normski]

Thanks Norm, All my coils read 100% solid connect, If I join Pos to Neg.
This meter always worked well on Suppressed H.T. leads, When I was in the motor trade.
The fact that it's reading 10k Low tension to H.T. Tells me the meter is doing something ?.
Cheers Bill.

It sounds like your meter isn't sensitive enough in the lower ohm range to show the primary winding (low tension) resistance.

 

[Comet Rider]

Bill,
Do you need it for next weekend?
If not I'll bring my decent MMeter with me to the Annual

Neil