Another coil question

[RDDave]

I know this subject has been beat to death and I have read many, many threads on this but I still have a couple of questions. Stock RD350B. The original coils test okay. But I found a couple of very small automobile style coils that had the the RD style electrical connectors already on them in an old parts stash that I have acquired. When tested, they threw a much stronger blue spark when tested. There are no markings on them to identify them. I have a VOM. What readings do I need to look for with these coils to know what all I need to do electrically to use them? The will physically fit in place of the originals and I would really like use them. I just don't want to create other problems by doing it. Thanks! 

[1976RD400C]

You can measure the primary winding resistance in your old coils and compare it to the auto ones. Test across the 2 small wires coming out of the coil. I think the oem ones should be about 3-4 ohms and if the auto ones are close to that it should be ok. If the auto coils are only 1 ohm they may get too warm and a ballast resistor will fix that, like what is on the RD400.

[m in sc]

they the round ones? emgos, which are actually replacements for 60s British bikes from the 60s, sold as 'high performance'. I hate those things as they might fit but its always a hack to get them in there.

^ the testing procedure is correct above.



 

[RDDave]

The coils look like half sized old car coils. I have a pic of them side by side to my originals if I can figure out how to post it. I will check the ohm readings. Actually, since they fit in between the frame tubes where the original mounts are, I should be able to secure them there.

[m in sc]

yup.

these, right?

https://www.lowbrowcustoms.com/products/emgo-12-volt-ignition-coils-pair-lucas-style

[RDDave]

The ones I have are all black, but who knows how old they are and things may have changed over that time. The original coils measured 4 and the auto style measured 4.7 across the small leads. Is that enough difference to cause problems with the points or condenser? I really appreciate the input on this. Thank you.
I tried to post a pic but couldn't figure out how to get it from my phone to this post.

[m in sc]

its fine. I bet they are old kawasaki s2 or s3 coils, they are the same but black. or they are lucas coils. either way, they are OLD so tread carefully, they may not last.

[RDDave]

Thank you.

[IR8D8R]

Lucas electrical parts 

Lucas: The Prince of Darkness. Motto: "Get home before dark."

Inventor of the intermittent wiper and self-dimming headlight.

The three-position Lucas switch: DIM, FLICKER, and OFF.
The other three switch settings: SMOKE, SPARK, and IGNITE.

3 step process for successfully using Lucas electrical parts:
1) Open box.
2) Remove part from box.
3) Throw both in bin.

Q: Wonder why you rarely see any more British cars? A: Lucas.

Japanese motorcycle producers credit Lucas with much of their success.

Alexander Graham Bell invented the Telephone.
Thomas Edison invented the Light Bulb.
Joseph Lucas invented the Short Circuit.

When replacing Lucas electrical parts, always buy two. It increases the odds of success to 50/50.

 I'm not saying that you shouldn't use Lucas electrics. They're great for faithful concourse restorations that are always trailered.

 I used to sell parts for vintage Jaguars and Land Rovers. I've seen a lot of bad Lucas parts and heard (and told) a lot of the jokes. the Jaguar guys get offended. MG, Triumph, and Land Rover guys shake their heads and look sad. I'm assuming the BSA, Norton, and Triumph MC guys are the same but I didn't sell MC parts. Pretty much all of the British forums have a thread like this.

IR8D8R

[85RZwade]

that's hilarious!

[1976RD400C]

A friend of mine had his headlight go out on his 60's Triumph while riding on a dark twisty road. Went in the ditch and down. He never forgave his bike for that.

[Brad-Man]

Lucas got a rude awakening when Ford bought Jaguar - more than 70% of Lucas parts were rejected by QC...

[dgorms]

My first real street bike was a 71 750 Commando! PO told me to check electrical connections frequently. I did it twice a month and dressed the points, never had a problem. Also did a nut and bolt at the same time.