Of coarse you should never sand the coil wire in a magneto, but you SHOULD sand the lacquer from the bottom side if the metal core where it bolts up to the crankcase, so it gets a good ground connection...Sanding the coils in the engine is a bad idea. The lacquer is there to insulate the wires in the coil. Best left untouched unless there is trouble. Do you still have spark? Is the coil sending power to the cdi? Seems like a lot of people have problems with the coil wire. (from the cdi to the plug)
What is the problem you are experiencing? Running the wrong plug could cause you a problem, so why not run the right plug? Try an NGK BP6HS plug, lots of us are running them and they work great..Could the wrong spark plug burn out my cdi or magneto?
Yes, CDI's have been known to fail, mine never have, but I have read about it enough in the forum... I can't confirm the cause of failure for others, I suspect it would be a bad solder connection inside the sealed CDI box. I run an automotive wire in my CDI, so far so good with about 1,500 miles on it. It could also be the crappy plug wire that fails on the cdi....My question is do CDI's really fry?
It apparently means your new CDI is measuring 2.5K Ohm from black wire to plug wire, but your used/failed CDI has gone up to 6.8k Ohm. This could be due to increased resistance in the plug wire or something inside the box. I haven't really dug into CDI design (yet) others have and are building their own, so they might have more to add....Here's a question then,
The normal black to spark wire is about 2.5 on the 20k ohm setting on a multimeter.
I've now had two CDI's die, and they now read 6.8 on the 20k setting. What does that number mean when it's higher or lower?
Did you disconnect the kill switch to make sure its not a problem, and make sure you isolate the white wire, check the connections between the CDI and magneto? Re soldering the magneto sometimes does the trick (when you have a poor connection to the core). Have you read this page yet?I guess i answered my own question:
http://motorbicycling.com/showthread.php?t=35058
Weird. I'm going to replace the magneto tomorrow morning and see if that fixes the no spark issue.
Pretty much, make sure the outer diameter of the wire is the same as the one in your cdi... I will paste in below from an older post I made about upgrading my plug wire....So do I just go to the auto parts store and ask for a generic set of spark plug wires? and cut off the 6 inches and spark plug adapter i want to use?
Is there a brand i need or is anything game?
Well, perhaps you might re-evaluate where you are mounting the CDI? It seems odd to go through so many, perhaps the CDI is getting vibrated excessively where it is mounted now? Just a thought.....All I know is my bike was running like a champ and I'm flying along and it just dies and I got no spark. And then today I get a new cdi, I install it and I got spark so I button it up, jump on it and try and start it and nothing, so I check the spark and it's gone. I understand the wiring on this thing, I had it running for a couple of weeks before this weird stuff started happening. I've re soldered all of the connections in case I had some cold connections and it's all taped of so it won't short out. My old cdi's readings seemed wrong and my magneto readings seem spot on. That's why I got a knew one.
I'm pretty sure I said this in my post earlier....So again, I answer my own question.
I did some searching and found the spark plugs for the '94 Chevy Astro Van or the '95 GMC Safari are the perfect match.
Plus both sides of each cable work with a spark plug, and a set of 6 cost 18 bucks. I now have 12 new spark plug cables for replacing on my CDI's.
Can't wait to get home so i can fire things up!